CI(pytest): Refactor common pytest arguments to files

[echoix]

Since pytest 8.2, pytest allows using a file to send an argument list (https://docs.pytest.org/en/stable/how-to/usage.html#args-from-file), using native argparse functionality (https://docs.python.org/3/library/argparse.html#fromfile-prefix-chars).

Since the different invocations of pytest in CI are repeated a couple times, and quoting rules is different in between shells (like the cmd vs powershell on Windows vs the other platforms), using argument files makes sense.
It allows to factor out duplicated arguments that needs to get updated at each place.

It is possible to use an argument file multiple times, and it is also possible to use an argument file inside an argument file, but I decided against, as for another use case, it was easier to have independent "building blocks" of common arguments when needing to not have one of them, but keep the other parts.

I had to update the pytest version on Windows, as the one provided by OSGeo4W is too old (8.1.1, it's been a little while).

TLDR: Changing pytest arguments in CI can be done once, and applied to all our files using arguments defined in separate files

[echoix]

If my PRs from last week could be looked at (and merged) before the weekend, I would be ready (after rebasing), to have a small subset of gunittest-based tests that would be run by pytest.

I was expecting that the small issues fixed in separate, independent PRs, would be easy to review

[wenzeslaus]

Unusual, but it makes sense. It generally meant for long lists by both argparse and pytest, but pytest highlights that syntax and we do have similar long list issues in GRASS (file parameter), compensating for the unusual nature of this.

[echoix]

My implementation of running working tests, and handling the discovery/exclusion for gunittest tests heavily uses this, and was not reasonable copying into each workflow.

[echoix]

If you could take a look at any of my open PRs, especially in these I'd appreciate it :)

• tests: Fix collection errors when importing tests have side effects #5541
• chore: Format yaml and workflow files #5543
• style: Fix raise-without-from-inside-except (B904) for pygrass Module #5545
• tests: Load "msvcrt" instead of "c" ctypes library on Windows #5546
• tests: Import CalledModuleError from grass.exceptions in test_names.py #5548

The full picture of what I want to submit after that is: echoix#404, + clean + rebase and a last fix for the difference between local osgeo4w install vs CI, or unselecting that failing test on windows