pip(deps-dev): bump mkdocs-mermaid2-plugin from 1.1.1 to 1.2.1

Bumps [mkdocs-mermaid2-plugin](https://github.com/fralau/mkdocs-mermaid2-plugin) from 1.1.1 to 1.2.1.
- [Release notes](https://github.com/fralau/mkdocs-mermaid2-plugin/releases)
- [Changelog](https://github.com/fralau/mkdocs-mermaid2-plugin/blob/master/CHANGELOG.md)
- [Commits](fralau/mkdocs-mermaid2-plugin@v1.1.1...v1.2.1)

---
updated-dependencies:
- dependency-name: mkdocs-mermaid2-plugin
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>