Bump gitpython from 3.1.11 to 3.1.18

Bumps [gitpython](https://github.com/gitpython-developers/GitPython) from 3.1.11 to 3.1.18.
- [Release notes](https://github.com/gitpython-developers/GitPython/releases)
- [Changelog](https://github.com/gitpython-developers/GitPython/blob/main/CHANGES)
- [Commits](gitpython-developers/GitPython@3.1.11...3.1.18)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

poetry.lock

@@ -15,7 +15,7 @@ semver = "^2.13.0"
 
 # Documentation generation dependencies.
 click = "<7.2"
-gitpython = "^3.1.1"
+gitpython = "^3.1.18"
 mdx_truly_sane_lists = "^1.2"
 mike = "^0.5.1"
 mkdocs = "^1.2.1"