`3.29.0` release seems to be broken on Python 3.9 and earlier due to `importlib_metadata` backport

[agriyakhetarpal]

CMake seems to use the importlib_metadata backport dependency for Python 3.8 and 3.9, but maybe it's not declaring that?

I noticed the failure in the CI logs, and then triggered a re-run just in case this was a one-off failure:

1. https://github.com/pybamm-team/PyBaMM/actions/runs/8436810245/job/23105126965
2. https://github.com/pybamm-team/PyBaMM/actions/runs/8436810245/job/23106957328

Edit: okay so it is declaring that, just in the optional dependencies table:

cmake-python-distributions/pyproject.toml

Lines 36 to 42 in 85a457b

	[project.optional-dependencies]
	test = [
	"coverage>=4.2",
	"importlib_metadata>=2.0; python_version<'3.10'",
	"pytest>=3.0.3",
	"pytest-cov>=2.4.0",

and I suppose it should be a required dependency too. It's being used here:

cmake-python-distributions/src/cmake/__init__.py

Lines 5 to 9 in 85a457b

	if sys.version_info < (3, 10):
	from importlib_metadata import distribution
	else:
	from importlib.metadata import distribution

[agriyakhetarpal]

I'm happy to fix this and add maybe add a test for this too, as it is deemed necessary.

[mloubout]

The issue is that importlib change is for python >= 3.8 not > 3.10 so it should be

if sys.version_info < (3, 8): 
     from importlib_metadata import distribution 
 else: 
     from importlib.metadata import distribution 

FYI ran into that issue in my CI as well.

[mloubout]

I filed a patch for it in case people agree it is correct. Can a release be made if the patch gets merged?

[braindevices]

this affect us too

[awni]

+1 would be great to have a patch for this.

[henryiii]

3.29.0 is yanked and we'll produce a 3.29.0.1 later today.

[henryiii]

New version out!