Bump mkdocs from 1.3.0 to 1.3.1 in /config (#73)

Bumps [mkdocs](https://github.com/mkdocs/mkdocs) from 1.3.0 to 1.3.1.
- [Release notes](https://github.com/mkdocs/mkdocs/releases)
- [Commits](mkdocs/mkdocs@1.3.0...1.3.1)

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

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

Author: dependabot[bot]

config/requirements.txt

@@ -1,4 +1,4 @@
-mkdocs==1.3.0
+mkdocs==1.3.1
 mkdocs-exclude==1.0.2
 mkdocs-material==8.3.9
 mkdocs-minify-plugin==0.5.0