ci: bump actions, move to rustsec/audit-check

[lcian]

• bump actions/checkout to v4
• bumpcodecov/codecov-action to v5 and pass secrets.CODECOV_TOKEN
• move from actions-rs/audit-check@v1 to rustsec/audit-check@v2 (pinned) which is more or less maintained

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.30%. Comparing base (605d36d) to head (d2f6054).
Report is 62 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #803      +/-   ##
==========================================
+ Coverage   72.79%   73.30%   +0.51%     
==========================================
  Files          66       62       -4     
  Lines        7804     7272     -532     
==========================================
- Hits         5681     5331     -350     
+ Misses       2123     1941     -182     

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[lcian]

Seems like tests are getting stuck on Windows.

[viglia]

Seems like tests are getting stuck on Windows.

@lcian seems like a transient error. I was able to run the Windows job fine.

[lcian]

Seems like tests are getting stuck on Windows.

@lcian seems like a transient error. I was able to run the Windows job fine.

@viglia
We've had a similar issue also in this PR #779
Windows CI would get stuck when putting more than one test in a single file, had to split them.
So it makes me suspicious that there is some underlying concurrency issue that for some reason happens only on Windows when running the tests.
There's also this #786 which I'm still looking into, could be related.

[lcian]

Probably just a flake, the issue I linked was not valid and anyway the CI changes have nothing to do this, merging.