paisa: add nixos-tests

Changed files
+4
pkgs
by-name
pa
paisa
+4
pkgs/by-name/pa/paisa/package.nix
···
];
versionCheckProgramArg = "version";
+
passthru.tests = {
+
inherit (nixosTests) paisa;
+
};
+
preBuild = ''
cp -r ${finalAttrs.frontend}/web/static ./web
'';