Bump mkdocs from 1.0.4 to 1.2.3

Bumps [mkdocs](https://github.com/mkdocs/mkdocs) from 1.0.4 to 1.2.3.
- [Release notes](https://github.com/mkdocs/mkdocs/releases)
- [Commits](mkdocs/mkdocs@1.0.4...1.2.3)

---
updated-dependencies:
- dependency-name: mkdocs
  dependency-type: direct:development
...

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