Bump markdown from 3.5.1 to 3.7

Bump markdown from 3.5.1 to 3.7

Bumps [markdown](https://github.com/Python-Markdown/markdown) from 3.5.1 to 3.7.
- [Release notes](https://github.com/Python-Markdown/markdown/releases)
- [Changelog](https://github.com/Python-Markdown/markdown/blob/master/docs/changelog.md)
- [Commits](https://github.com/Python-Markdown/markdown/compare/3.5.1...3.7)

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

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