Switch usage to skip_file_prefixes instead of stacklevel when it makes sense

[Simon Charette]

In most of our usages of warnings.warn (and almost every usage that relates to deprecation warnings) we want them to be associated to the first out-of-as that's the most likely location that can be adjusted to avoid the warning.

In order to achieve this goal we've historically attempted to pass a fixed stacklevel to warnings.warn which can sometimes ​be tricky and error prone depending on how nested and convoluted the user or third-party app offending call site might be. In other cases ​we've opted not to provide a stacklevel at all as determining the offending call site under all circumstances is impossible.

Well it appears that this is a problem that Python 3.12 allows frameworks to address in a better way with ​the introduction of warnings.warn(skip_file_prefixes: tuple[str] | None). This new feature would allow us to ensure that the proper offending call site is referenced when emitting from a deeply nested call site where stacklevel is inappropriate.

Since this is a Python 3.12+ feature I'd suggest we introduce a get_non_django_stacklevel() -> int (better name welcome) function that could be used to pass to warnings.warn(stacklevel) until we drop support for Python 3.11.

[Natalia Bidart]

Hello Simon, as always thank you for your detailed and thorough report.

I agree with your proposal, I think this would help reducing the mistakes and overall improve the contributing experience. I'm setting this version to dev since this new feature should target 5.2 at this point.

[Mohammad Salehi]

Hello, If you agree, I would like to review this issue and start working on it ?
Thank you.

[Simon Charette]

I think we might want to wait for the patch for #35666 to land before committing efforts here Mohammad.