chore(deps): bump markdown from 3.5 to 3.5.1

Bumps [markdown](https://github.com/Python-Markdown/markdown) from 3.5 to 3.5.1.
- [Release notes](https://github.com/Python-Markdown/markdown/releases)
- [Changelog](https://github.com/Python-Markdown/markdown/blob/master/docs/changelog.md)
- [Commits](Python-Markdown/markdown@3.5...3.5.1)

---
updated-dependencies:
- dependency-name: markdown
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.txt

@@ -10,7 +10,7 @@ geoalchemy2==0.4.2
 geojson==3.0.1
 geomet==1.0.0
 kombu==5.3.2
-Markdown==3.5 # at next update, please remove replace_marker() function in toc extension 
+Markdown==3.5.1 # at next update, please remove replace_marker() function in toc extension 
 phpserialize==1.3.0 # phpserialize is only required during the migration
 psycopg2==2.9.9
 pyjwt==1.7.1