MetadataPathFinder has `find_distributions` as a classmethod in CPython

[jaraco]

Today I noticed that in CPython, the find_distributions is a classmethod:

importlib_metadata/Lib/importlib/metadata/__init__.py

Lines 774 to 777 in a573be9

	@classmethod
	def find_distributions(
	cls, context=DistributionFinder.Context()
	) -> Iterable["PathDistribution"]:

But it's an instance method in importlib_metadata. I think it can be made a classmethod in both cases to reduce the divergence. I'd like to investigate to see if there was a reason for the divergence.

[jaraco]

It looks like the classmethod goes back to 83b48ec, suggesting the divergence happened as part of the integration effort with CPython, so probably could have been made a classmethod in importlib_metadata as well.