For the time being, when `setuptools.build_meta` is called,
`egg_info.egg_base` is accidentally set to the project root between the
several calls to the different build hooks.

This means that if the hooks are called, they will try to overwrite
`setuptools.egg-info/PKG-INFO`, and for a very short interval of time it
will be an empty file.

Another process may then try to simultaneously use `importlib.metadata`
to list entry-points. However to sort entry-points, `importlib.metadata`
will try to read the `Name` field in the `PKG-INFO/METADATA` files and
will raise an error/warning if that file is empty.

This commit tries to use `os.replace` to avoid having an empty PKG-INFO
while `importlib.metadata` is used.

Remove the msvc hack that was applied if numpy.distutils were loaded
prior to Numpy 1.11.2.  These versions date back to June 2016 and no
longer build with Python 3.7.  At the same time, the hack relies
on packaging.version.LegacyVersion that is removed in packaging 22.0.

This turns get_metadata_version into a method on DistributionMetadata,
populated either by inferrence (in the case of package metadata
specified in `setup`) or from the data in a specified PKG-INFO file.

To populate metadata_version from PKG-INFO, we need to monkey patch
read_pkg_file in addition to write_pkg_file.