Bump gitpython from 2.1.15 to 3.1.7
Bumps [gitpython](https://github.com/gitpython-developers/GitPython) from 2.1.15 to 3.1.7.
- [Release notes](https://github.com/gitpython-developers/GitPython/releases)
- [Changelog](https://github.com/gitpython-developers/GitPython/blob/master/CHANGES)
- [Commits](https://github.com/gitpython-developers/GitPython/compare/2.1.15...3.1.7)
Signed-off-by: dependabot-preview[bot] <[email protected]>