Bump markdown from 3.3.7 to 3.4.4

Bumps [markdown](https://github.com/Python-Markdown/markdown) from 3.3.7 to 3.4.4.
- [Changelog](https://github.com/Python-Markdown/markdown/blob/master/docs/change_log/release-2.6.md)
- [Commits](Python-Markdown/markdown@3.3.7...3.4.4)

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

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

requirements.txt

@@ -1,4 +1,4 @@
-markdown == 3.3.7
+markdown == 3.4.4
 markdown_include == 0.8.1
 mdx_truly_sane_lists == 1.3
 mkdocs == 1.5.1