Bump mkdocstrings[python-legacy] from 0.19.1 to 0.22.0 (#709)

Bumps [mkdocstrings[python-legacy]](https://github.com/mkdocstrings/mkdocstrings) from 0.19.1 to 0.22.0.
- [Release notes](https://github.com/mkdocstrings/mkdocstrings/releases)
- [Changelog](https://github.com/mkdocstrings/mkdocstrings/blob/master/CHANGELOG.md)
- [Commits](mkdocstrings/mkdocstrings@0.19.1...0.22.0)

---
updated-dependencies:
- dependency-name: mkdocstrings[python-legacy]
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements.txt

@@ -8,7 +8,7 @@ mkdocs==1.4.2
 mkdocs-autorefs==0.3.1
 mkdocs-material==9.1.5
 mkdocs-material-extensions==1.1.1
-mkdocstrings[python-legacy]==0.19.1
+mkdocstrings[python-legacy]==0.22.0
 jinja2==3.1.2
 
 # Packaging