Deprecate passing iterator argvalues to parametrize

[bluetech]

Fixes #13409 by deprecating non-Collection argvalues as described in the issue. The deprecation is both in runtime and in type checking time (via the new @warning.deprecated decorator, though it's not enabled in mypy by default yet).

[bluetech]

TODO: Avoid showing the two overloads for Metafunc.parameterize in the API reference.

[bluetech]

TODO: Avoid showing the two overloads for Metafunc.parameterize in the API reference.

Tried a few things (TYPE_CHECKING, if False, sphinx autodoc hooks) but couldn't make sphinx ignore the overloads (sphinx-doc/sphinx#10351). There's probably a way but I'm just going to remove the @deprecated from Metafunc.parametrize. It will still be on @pytest.mark.parametrize which is not autodoc'ed so no problem.

[bluetech]

• Fixed @nicoddemus's review comments.
• Removed @deprecated from Metafunc (see comment above).
• Improved the runtime deprecation message, since the @pytest.mark.parametrize is not on the stack when metafunc.parametrize is called, the stacklevel is useless for it. So I added the nodeid to the message.

[nicoddemus]

Awesome!

I understand you don't want to ship this into 9.0?

[bluetech]

I understand you don't want to ship this into 9.0?

Gotta know where to stop :) This can go in the next release.

[nicoddemus]

Fair enough. 😁