build(deps): bump tornado from 6.4.1 to 6.4.2 (#3470)

Bumps [tornado](https://github.com/tornadoweb/tornado) from 6.4.1 to 6.4.2.
- [Changelog](https://github.com/tornadoweb/tornado/blob/v6.4.2/docs/releases.rst)
- [Commits](tornadoweb/tornado@v6.4.1...v6.4.2)

---
updated-dependencies:
- dependency-name: tornado
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -21,4 +21,4 @@ pymdown-extensions==10.12
 PyYAML==6.0.2
 six==1.16.0
 tabulate==0.9.0
-tornado==6.4.1
+tornado==6.4.2