Replace pkg_resources with importlib.metadata

[ziegenberg]

The documentation of pkg_resources suggests that the use of pkg_resources is discouraged in favour of importlib.resources, importlib.metadata and their backports as pkg_resources is older and less efficient. See also: https://docs.python.org/3/library/importlib.metadata.html

Removes also one unused function attrs().

[ssbarnea]

I think you missed to update requirements for older version of python.

Almost for sure you are missing something like https://github.com/ansible-community/molecule/blob/main/setup.cfg#L68

[ziegenberg]

I've rebased onto the current main. And I changed the way importlib.metadata is imported:

if sys.version_info >= (3, 8):
    from importlib.metadata import version
else:
    from importlib_metadata import version

This should now work with the automated package discovery of setuptools.

[ssbarnea]

I think you misunderstood, our package manifest does not list importlib-metadata as a dependency for older versions of python, something that is a bug, a bug introduced by this change.

Look at my link from initial comment, it is an example of how to define that conditional dependency.

Probably our test pipelines do not fail only by chance, as another packages already installed importlib_metadata. Still, if we import it from our code it must be listed as a direct dependency.

[ziegenberg]

Sorry, I mixed up automatic package discovery and dependencies management. Should be fixed now.