Get version from package metadata rather than hardcoded string #31
Description
Use importlib.metadata to find the version of the installed package. See https://gitlab.wikimedia.org/repos/ci-tools/commit-message-validator/-/commit/64a3b58411f8dd3773516504556d22bee1465ff1 as an implementation example including support for older versions of Python.