Fix version duplication

[k-collie]

Version is specified in:

• setup.py
• idlbridge/VERSION
• init.py as global __version__

only the setup.py number was updated in the last update, so they are currently out of sync.

The VERSION file is not referenced anywhere except MANIFEST.in. It should be removed.

__version__ in init.py should use importlib.metadata.version or importlib_metadata.version instead of being duplicated.