json-rpc is not compatible with ocaml-5
Uses the Stream module
```
=== ERROR while compiling json-rpc.0.5.0-0 ===================================#
context 2.2.0~alpha~dev | linux/x86_64 | ocaml-base-compiler.5.0.0 | file:///home/opam/opam-repository
path ~/.opam/5.0/.opam-switch/build/json-rpc.0.5.0-0
command ~/.opam/opam-init/hooks/sandbox.sh build ocaml setup.ml -configure --prefix /home/opam/.opam/5.0
exit-code 2
env-file ~/.opam/log/json-rpc-8-bfcac9.env
output-file ~/.opam/log/json-rpc-8-bfcac9.out
File "./setup.ml", line 575, characters 4-15:
575 | Stream.from next
^^^^^^^^^^^
Error: Unbound module Stream
```
Signed-off-by: Marcello Seri <marcello.seri@gmail.com>