pytest: Enhance logging output with colors and summary

[echoix]

To help read CI logs more easily, enabled colored output where possible (in CI only, for pytest workflow).

For pytest itself:

• added verbose output so we can see what test is running
• added colors so error results are WAY easier to read through (it even has syntax highlighting for python code)
• added a short summary of passed/skipped/failed/xfailed tests
• added the display of top durations for the test or the setup (I finally chose to not limit the number of items to output, but to raise the minimum duration for that list to ignore all durations under 0.5 sec instead of the default of 0.005s. 0.5s seems reasonable for what a slow unit test should be in my opinion. We have setup and test steps that take over 9 seconds as we can see from that)

Images

Colored pip with cache misses:

For errors/warnings, some I intentionnaly added to see how it looked
Colored gcc:

Colored pytest:

[echoix]

I finally removed the GCC colors since the builds fails with it, and don't fail if I remove it afterwards. I don't understand why, but since they are not super obvious, I'm kicking it out of the scope.

[echoix]

This is a side PR from what I was working on simultaneously: adding ccache or sccache, whichever was better. For now, from the numbers I have, it isn't worth it for pytest, but for windows, it might be worth it:

• On cache hit: I have 95 seconds saved with ccache (8min 33 to 8min37sec vs 10min12sec before)
• When building a cache: time increased to 12min39sec vs 10min12 before (2min27 more)

Both can take 6 seconds before and after to push pull the cache.

Cache from main can be used in PRs (in theory), but cache from PRs are scoped to the PR (ie: a PR can fall back to main's cache if it doesn't exist).

I'm not decided yet and didn't manage to make sccache work, as it originally had better support on windows.