Bump joblib from 1.1.0 to 1.2.0 in /docs/mkdocs

Bumps [joblib](https://github.com/joblib/joblib) from 1.1.0 to 1.2.0.
- [Release notes](https://github.com/joblib/joblib/releases)
- [Changelog](https://github.com/joblib/joblib/blob/master/CHANGES.rst)
- [Commits](https://github.com/joblib/joblib/compare/1.1.0...1.2.0)

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

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

docs/mkdocs/requirements.txt

@@ -12,7 +12,7 @@ httplib2==0.20.4
 idna==3.3
 importlib-metadata==4.12.0
 Jinja2==3.1.2
-joblib==1.1.0
+joblib==1.2.0
 jsmin==3.0.1
 livereload==2.6.3
 lunr==0.6.2