Bump markdown from 3.4.1 to 3.5

Bumps [markdown](https://github.com/Python-Markdown/markdown) from 3.4.1 to 3.5.
- [Changelog](https://github.com/Python-Markdown/markdown/blob/master/docs/changelog.md)
- [Commits](Python-Markdown/markdown@3.4.1...3.5)

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

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

src/requirements.txt

@@ -32,7 +32,7 @@ idna==3.4
 isodate==0.6.1
 isort==5.10.1
 lazy-object-proxy==1.9.0
-Markdown==3.4.1
+Markdown==3.5
 mccabe==0.7.0
 msrest==0.7.1
 mypy-extensions==1.0.0