chore: update codecov/codecov-action to v4

[vil02]

Description

Toneless uploads to codecov are no longer supported. This PR updates codecov/codecov-action to v4 and changes the upload workflow in such a way that:

• tokenless upload it used for PRs created from forks,
• upload with token is used for every other occasion.

Before merge: please make sure to add the token as CODECOV_TOKEN into the repo secrets. (Token was added)

It seems that both of the branches work:

• tokenless,
• without token - the job has failed due to the lack of the token in my fork, but the branch was correctly selected.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (17d5dad) 94.68% compared to head (1ba8b44) 94.68%.

Additional details and impacted files

@@ Coverage Diff @@ ## master #670 +/- ## ======================================= Coverage 94.68% 94.68% ======================================= Files 292 292 Lines 23258 23258 ======================================= Hits 22022 22022 Misses 1236 1236 

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[vil02]

@siriak: I think you can merge it. My strong conjecture is that the push will go through the upload with token branch.

[vil02]

@siriak thanks! I just checked, everything works as expected.