migrate from pkg_resources

[profjsb]

Using baselayer to install packages via requirements.txt fails on anything but <package_name>==<version>. If we want to use a specific git hash in requirements.txt (via git+https://...@hash#egg=...) then pip itself works but dependency checking in baselayer does not.

Documentation for pkg_resources says:

Use of pkg_resources is discouraged in favor of importlib.resources, importlib.metadata, and their backports (importlib_resources, [importlib_metadata] (https://pypi.org/project/importlib_metadata)). Please consider using those libraries instead of pkg_resources.