Bump markdown from 3.9 to 3.10

Bumps [markdown](https://github.com/Python-Markdown/markdown) from 3.9 to 3.10.
- [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@3.9.0...3.10.0)

---
updated-dependencies:
- dependency-name: markdown
  dependency-version: '3.10'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements.txt

@@ -1,5 +1,5 @@
 click==8.2.1 # click 8.2.2 breaks use_directory_urls somehow?
-Markdown==3.9
+Markdown==3.10
 markdown-include==0.8.1
 mkdocs==1.6.1
 mkdocs-cinder==1.2.0