CI: Ensure code coverage is always uploaded

[QuLogic]

PR summary

If code coverage is not uploaded on failure, then overall coverage can suffer mysteriously (e.g., if a mac system failed, then it would appear as if backend_macosx.py was not tested). Codecov would then show several "indirect changes" that are spurious.

On GitHub Actions, if you don't have any status check function in the if entry, then it is treated as success() && (whatever else you had), so put in an explicit check.

Azure also had no condition, so defaulted to only-on-success.

Also, fix the image-cleanup script, which would only run on success instead of failure, where it would be useful.

PR checklist

• [n/a] "closes #0000" is in the body of the PR description to link the related issue
• new and changed code is tested
• [n/a] Plotting related features are demonstrated in an example
• [n/a] New Features and API Changes are noted with a directive and release note
• [n/a] Documentation complies with general and docstring guidelines

[QuLogic]

OK, this looks good; coverage is being uploaded even on failure on all the runs. I'm not sure if we should upload Cygwin coverage, since it's not done on all PRs too. Maybe there's a way to keep that separate.

Also, the script to remove passing images is now working, though I see it doesn't really clean up as much as it can.

One other thing is that it appears that Azure only uploads on Linux; it is using the Bash uploader, which is supposed to be broken, but still works there. However, it stopped working on other platforms. I think we would need to set up a token in order to get the new uploader working.

[ksunden]

I think preventing cygwin from uploading is probably fine. If having it would cause main to have more coverage than PRs, that would make almost all runs fail coverage check I think.

Azure may be worth either fixing (could be here or in a followup) or removing coverage entirely (if its not getting us additional coverage/hasn't been working anyway).

I would leave any adjustments to the upload cleaner for a separate PR.

[QuLogic]

I removed Cygwin, as it would just cause extra flapping, since only main runs it and PRs only run it conditionally. I did leave the coverage reporting to the terminal just in case someone wanted to browse it.

[tacaswell]

Agree about both not uploading from cygwin and defering fixing uploading on non-linux azure to a follow on PR.

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

git checkout v3.9.x
git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

git cherry-pick -x -m1 3ee509d14f5a624f1d99c3a1727810e9c4989258

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

git commit -am 'Backport PR #28164: CI: Ensure code coverage is always uploaded'

4. Push to a named branch:

git push YOURFORK v3.9.x:auto-backport-of-pr-28164-on-v3.9.x

5. Create a PR against branch v3.9.x, I would have named this PR:

"Backport PR #28164 on branch v3.9.x (CI: Ensure code coverage is always uploaded)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the Still Needs Manual Backport label once the PR gets merged.

If these instructions are inaccurate, feel free to suggest an improvement.