Move to ppx_expect v0.17.0

[voodoos]

No description provided.

[rgrinberg]

I'll update nix in a later PR

[voodoos]

Actually ppx_expect.0.17.0 requires at least OCaml 5.1.

We can either disable testing on 4.14 or wait until we merge 5.2 support.

[coveralls]

Pull Request Test Coverage Report for Build 4550

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 131 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.09%) to 21.935%

---

Files with Coverage Reduction	New Missed Lines	%
ocaml-lsp-server/src/ocaml_lsp_server.ml	131	36.54%

Totals
Change from base Build 4536:	0.09%
Covered Lines:	5589
Relevant Lines:	25480

---

💛 - Coveralls