Allow setuptools-git-versioning 2.x

[musicinmybrain]

Pull request

Allow the current release of setuptools-git-versioning (2.0.0) by raising the version bound from <2 to <3. (I did not file an issue for this.)

Version 2.0.0 has several breaking changes, described in https://setuptools-git-versioning.readthedocs.io/en/stable/changelog.html#change-2.0.0, but none of them appear relevant for this project.

How Has This Been Tested?

$ python3 -m build
$ cd dist
$ ls -1
pdfminer.six-20221105.post23+git.f02a1b80-py3-none-any.whl
pdfminer.six-20221105.post23+git.f02a1b80.tar.gz
$ python3 -m wheel unpack pdfminer.six-20221105.post23+git.f02a1b80-py3-none-any.whl
$ grep -E '^Version:' pdfminer.six-20221105.post23+git.f02a1b80/pdfminer.six-20221105.post23+git.f02a1b80.dist-info/METADATA 
Version: 20221105.post23+git.f02a1b80

https://setuptools-git-versioning.readthedocs.io/en/stable/changelog.html#change-2.0.0

Checklist

• I have read CONTRIBUTING.md.
• I have added a concise human-readable description of the change to CHANGELOG.md.
• I have tested that this fix is effective or that this feature works.
• I have added docstrings to newly created methods and classes. N/A, no code changes
• I have updated the README.md and the readthedocs documentation. Or verified that this is not necessary.