Bump markdown from 3.8.2 to 3.9 (#1121)

Bumps [markdown](https://github.com/Python-Markdown/markdown) from 3.8.2 to 3.9.
- [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@3.8.2...3.9.0)

---
updated-dependencies:
- dependency-name: markdown
  dependency-version: '3.9'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Max Ostapenko <1611259+max-ostapenko@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -2,7 +2,7 @@ Flask==3.1.2
 flask-talisman==1.1.0
 google-cloud-storage==3.3.0
 gunicorn==23.0.0
-markdown==3.8.2
+markdown==3.9
 pytest==8.4.2
 pytest-watch==4.2.0
 pytest-cov==6.2.1