Bump setuptools from 57.5.0 to 65.5.1 in /docs

Bumps [setuptools](https://github.com/pypa/setuptools) from 57.5.0 to 65.5.1.
- [Release notes](https://github.com/pypa/setuptools/releases)
- [Changelog](https://github.com/pypa/setuptools/blob/main/NEWS.rst)
- [Commits](pypa/setuptools@v57.5.0...v65.5.1)

---
updated-dependencies:
- dependency-name: setuptools
  dependency-type: direct:production
...

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

docs/preinstall_requirements.txt

@@ -2,4 +2,4 @@
 # For some odd reason, readthedocs uses a really old version of setuptools
 # Note: as of v58.0.0 the `2to3` option for setup() is gone which breaks
 # ALL installs of sphinx-bootstrap-theme
-setuptools==57.5.0
+setuptools==65.5.1