cfstream is not compatible with core v0.17
It fails with
```
=== ERROR while compiling cfstream.1.3.2 =====================================#
context 2.2.0~alpha~dev | linux/x86_64 | ocaml-base-compiler.4.14.1 | file:///home/opam/opam-repository
path ~/.opam/4.14/.opam-switch/build/cfstream.1.3.2
command ~/.opam/opam-init/hooks/sandbox.sh build dune build -p cfstream -j 71
exit-code 1
env-file ~/.opam/log/cfstream-7-3b14b3.env
output-file ~/.opam/log/cfstream-7-3b14b3.out
(cd _build/default && /home/opam/.opam/4.14/bin/ocamlc.opt -w -40 -g -bin-annot -I lib/.CFStream.objs/byte -I /home/opam/.opam/4.14/lib/base -I /home/opam/.opam/4.14/lib/base/base_internalhash_types -I /home/opam/.opam/4.14/lib/base/caml -I /home/opam/.opam/4.14/lib/base/md5 -I /home/opam/.opam/4.14/lib/base/shadow_stdlib -I /home/opam/.opam/4.14/lib/base_bigstring -I /home/opam/.opam/4.14/lib/base_quickcheck -I /home/opam/.opam/4.14/lib/base_quickcheck/ppx_quickcheck/runtime -I /home/opam/.opam/4.14/lib/bin_prot -I /home/opam/.opam/4.14/lib/bin_prot/shape -I /home/opam/.opam/4.14/lib/camlp-streams -I /home/opam/.opam/4.14/lib/core -I /home/opam/.opam/4.14/lib/core/base_for_tests -I /home/opam/.opam/4.14/lib/core/command -I /home/opam/.opam/4.14/lib/core/filename_base -I /home/opam/.opam/4.14/lib/core/heap_block -I /home/opam/.opam/4.14/lib/core/univ_map -I /home/opam/.opam/4.14/lib/core/validate -I /home/opam/.opam/4.14/lib/core_kernel -I /home/opam/.opam/4.14/lib/fieldslib -I /home/opam/.opam/4.14/lib/int_repr -I /home/opam/.opam/4.14/lib/jane-street-headers -I /home/opam/.opam/4.14/lib/parsexp -I /home/opam/.opam/4.14/lib/ppx_assert/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_bench/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_compare/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_enumerate/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_expect/collector -I /home/opam/.opam/4.14/lib/ppx_expect/common -I /home/opam/.opam/4.14/lib/ppx_expect/config -I /home/opam/.opam/4.14/lib/ppx_expect/config_types -I /home/opam/.opam/4.14/lib/ppx_hash/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_here/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_inline_test/config -I /home/opam/.opam/4.14/lib/ppx_inline_test/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_log/types -I /home/opam/.opam/4.14/lib/ppx_module_timer/runtime -I /home/opam/.opam/4.14/lib/ppx_sexp_conv/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_stable_witness/runtime -I /home/opam/.opam/4.14/lib/ppx_stable_witness/stable_witness -I /home/opam/.opam/4.14/lib/sexplib -I /home/opam/.opam/4.14/lib/sexplib0 -I /home/opam/.opam/4.14/lib/splittable_random -I /home/opam/.opam/4.14/lib/stdio -I /home/opam/.opam/4.14/lib/time_now -I /home/opam/.opam/4.14/lib/typerep -I /home/opam/.opam/4.14/lib/variantslib -no-alias-deps -open CFStream__ -o lib/.CFStream.objs/byte/cFStream__CFStream_stream.cmi -c -intf lib/CFStream_stream.mli)
File "lib/CFStream_stream.mli", line 6, characters 5-16:
6 | open Core_kernel
^^^^^^^^^^^
Alert deprecated: module Core_kernel
[since 2021-05] Use [Core] -- [Core_kernel] was renamed as [Core]
(cd _build/default && /home/opam/.opam/4.14/bin/ocamlc.opt -w -40 -g -bin-annot -I lib/.CFStream.objs/byte -I /home/opam/.opam/4.14/lib/base -I /home/opam/.opam/4.14/lib/base/base_internalhash_types -I /home/opam/.opam/4.14/lib/base/caml -I /home/opam/.opam/4.14/lib/base/md5 -I /home/opam/.opam/4.14/lib/base/shadow_stdlib -I /home/opam/.opam/4.14/lib/base_bigstring -I /home/opam/.opam/4.14/lib/base_quickcheck -I /home/opam/.opam/4.14/lib/base_quickcheck/ppx_quickcheck/runtime -I /home/opam/.opam/4.14/lib/bin_prot -I /home/opam/.opam/4.14/lib/bin_prot/shape -I /home/opam/.opam/4.14/lib/camlp-streams -I /home/opam/.opam/4.14/lib/core -I /home/opam/.opam/4.14/lib/core/base_for_tests -I /home/opam/.opam/4.14/lib/core/command -I /home/opam/.opam/4.14/lib/core/filename_base -I /home/opam/.opam/4.14/lib/core/heap_block -I /home/opam/.opam/4.14/lib/core/univ_map -I /home/opam/.opam/4.14/lib/core/validate -I /home/opam/.opam/4.14/lib/core_kernel -I /home/opam/.opam/4.14/lib/fieldslib -I /home/opam/.opam/4.14/lib/int_repr -I /home/opam/.opam/4.14/lib/jane-street-headers -I /home/opam/.opam/4.14/lib/parsexp -I /home/opam/.opam/4.14/lib/ppx_assert/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_bench/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_compare/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_enumerate/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_expect/collector -I /home/opam/.opam/4.14/lib/ppx_expect/common -I /home/opam/.opam/4.14/lib/ppx_expect/config -I /home/opam/.opam/4.14/lib/ppx_expect/config_types -I /home/opam/.opam/4.14/lib/ppx_hash/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_here/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_inline_test/config -I /home/opam/.opam/4.14/lib/ppx_inline_test/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_log/types -I /home/opam/.opam/4.14/lib/ppx_module_timer/runtime -I /home/opam/.opam/4.14/lib/ppx_sexp_conv/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_stable_witness/runtime -I /home/opam/.opam/4.14/lib/ppx_stable_witness/stable_witness -I /home/opam/.opam/4.14/lib/sexplib -I /home/opam/.opam/4.14/lib/sexplib0 -I /home/opam/.opam/4.14/lib/splittable_random -I /home/opam/.opam/4.14/lib/stdio -I /home/opam/.opam/4.14/lib/time_now -I /home/opam/.opam/4.14/lib/typerep -I /home/opam/.opam/4.14/lib/variantslib -intf-suffix .ml -no-alias-deps -open CFStream__ -o lib/.CFStream.objs/byte/cFStream__CFStream_stream.cmo -c -impl lib/CFStream_stream.ml)
File "lib/CFStream_stream.ml", line 1, characters 5-16:
1 | open Core_kernel
^^^^^^^^^^^
Alert deprecated: module Core_kernel
[since 2021-05] Use [Core] -- [Core_kernel] was renamed as [Core]
File "lib/CFStream_stream.ml", line 86, characters 18-32:
86 | | None -> raise Caml.Not_found
^^^^^^^^^^^^^^
Alert deprecated: module Core_kernel.Caml
[since 2023-01] use Stdlib instead of Caml
File "lib/CFStream_stream.ml", line 290, characters 35-40:
290 | let group_by xs ~eq = group_aux xs ident eq
^^^^^
Error: Unbound value ident
(cd _build/default && /home/opam/.opam/4.14/bin/ocamlopt.opt -w -40 -g -I lib/.CFStream.objs/byte -I lib/.CFStream.objs/native -I /home/opam/.opam/4.14/lib/base -I /home/opam/.opam/4.14/lib/base/base_internalhash_types -I /home/opam/.opam/4.14/lib/base/caml -I /home/opam/.opam/4.14/lib/base/md5 -I /home/opam/.opam/4.14/lib/base/shadow_stdlib -I /home/opam/.opam/4.14/lib/base_bigstring -I /home/opam/.opam/4.14/lib/base_quickcheck -I /home/opam/.opam/4.14/lib/base_quickcheck/ppx_quickcheck/runtime -I /home/opam/.opam/4.14/lib/bin_prot -I /home/opam/.opam/4.14/lib/bin_prot/shape -I /home/opam/.opam/4.14/lib/camlp-streams -I /home/opam/.opam/4.14/lib/core -I /home/opam/.opam/4.14/lib/core/base_for_tests -I /home/opam/.opam/4.14/lib/core/command -I /home/opam/.opam/4.14/lib/core/filename_base -I /home/opam/.opam/4.14/lib/core/heap_block -I /home/opam/.opam/4.14/lib/core/univ_map -I /home/opam/.opam/4.14/lib/core/validate -I /home/opam/.opam/4.14/lib/core_kernel -I /home/opam/.opam/4.14/lib/fieldslib -I /home/opam/.opam/4.14/lib/int_repr -I /home/opam/.opam/4.14/lib/jane-street-headers -I /home/opam/.opam/4.14/lib/parsexp -I /home/opam/.opam/4.14/lib/ppx_assert/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_bench/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_compare/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_enumerate/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_expect/collector -I /home/opam/.opam/4.14/lib/ppx_expect/common -I /home/opam/.opam/4.14/lib/ppx_expect/config -I /home/opam/.opam/4.14/lib/ppx_expect/config_types -I /home/opam/.opam/4.14/lib/ppx_hash/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_here/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_inline_test/config -I /home/opam/.opam/4.14/lib/ppx_inline_test/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_log/types -I /home/opam/.opam/4.14/lib/ppx_module_timer/runtime -I /home/opam/.opam/4.14/lib/ppx_sexp_conv/runtime-lib -I /home/opam/.opam/4.14/lib/ppx_stable_witness/runtime -I /home/opam/.opam/4.14/lib/ppx_stable_witness/stable_witness -I /home/opam/.opam/4.14/lib/sexplib -I /home/opam/.opam/4.14/lib/sexplib0 -I /home/opam/.opam/4.14/lib/splittable_random -I /home/opam/.opam/4.14/lib/stdio -I /home/opam/.opam/4.14/lib/time_now -I /home/opam/.opam/4.14/lib/typerep -I /home/opam/.opam/4.14/lib/variantslib -intf-suffix .ml -no-alias-deps -open CFStream__ -o lib/.CFStream.objs/native/cFStream__CFStream_stream.cmx -c -impl lib/CFStream_stream.ml)
File "lib/CFStream_stream.ml", line 1, characters 5-16:
1 | open Core_kernel
^^^^^^^^^^^
Alert deprecated: module Core_kernel
[since 2021-05] Use [Core] -- [Core_kernel] was renamed as [Core]
File "lib/CFStream_stream.ml", line 86, characters 18-32:
86 | | None -> raise Caml.Not_found
^^^^^^^^^^^^^^
Alert deprecated: module Core_kernel.Caml
[since 2023-01] use Stdlib instead of Caml
File "lib/CFStream_stream.ml", line 290, characters 35-40:
290 | let group_by xs ~eq = group_aux xs ident eq
^^^^^
Error: Unbound value ident
```
Signed-off-by: Marcello Seri <marcello.seri@gmail.com>