chore(deps): update mkdocs requirement from >=1.6 to >=1.6.1 in /docs

Updates the requirements on [mkdocs](https://github.com/mkdocs/mkdocs) to permit the latest version.
- [Release notes](https://github.com/mkdocs/mkdocs/releases)
- [Commits](mkdocs/mkdocs@1.6.0...1.6.1)

---
updated-dependencies:
- dependency-name: mkdocs
  dependency-version: 1.6.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

docs/requirements.txt

@@ -8,6 +8,6 @@
 # `actions/setup-python` `cache: pip` key) and by anyone running
 # `mkdocs serve` locally.
 
-mkdocs>=1.6
+mkdocs>=1.6.1
 mkdocs-material>=9.7.7
 pymdown-extensions>=11.0.2