Upgrade: Bump gitpython from 3.1.18 to 3.1.20 (#162)

Bumps [gitpython](https://github.com/gitpython-developers/GitPython) from 3.1.18 to 3.1.20.
- [Release notes](https://github.com/gitpython-developers/GitPython/releases)
- [Changelog](https://github.com/gitpython-developers/GitPython/blob/main/CHANGES)
- [Commits](gitpython-developers/GitPython@3.1.18...3.1.20)

---
updated-dependencies:
- dependency-name: gitpython
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -7,7 +7,7 @@ certifi==2021.5.30
 chardet==4.0.0
 click==8.0.1
 gitdb==4.0.7
-GitPython==3.1.18
+GitPython==3.1.20
 h11==0.12.0
 httpcore==0.13.6
 httpx==0.18.2