[dependency]: Bump mistune from 0.8.4 to 3.1.0

Bumps [mistune](https://github.com/lepture/mistune) from 0.8.4 to 3.1.0.
- [Release notes](https://github.com/lepture/mistune/releases)
- [Changelog](https://github.com/lepture/mistune/blob/master/docs/changes.rst)
- [Commits](lepture/mistune@v0.8.4...v3.1.0)

---
updated-dependencies:
- dependency-name: mistune
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -20,4 +20,4 @@ sphinxcontrib.mermaid==0.9.2
 sphinxcontrib.ghcontributors==0.2.3
 m2r2==0.3.2
 GitPython==3.1.37
-mistune==0.8.4
+mistune==3.1.0