Bump tornado from 6.4 to 6.4.1

Bumps [tornado](https://github.com/tornadoweb/tornado) from 6.4 to 6.4.1.
- [Changelog](https://github.com/tornadoweb/tornado/blob/master/docs/releases.rst)
- [Commits](tornadoweb/tornado@v6.4.0...v6.4.1)

---
updated-dependencies:
- dependency-name: tornado
  dependency-type: direct:production
...

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

requirements.txt

@@ -20,6 +20,6 @@ python-dateutil==2.8.2
 PyYAML==6.0.1
 selenium==4.2.0  # needs fixes before update
 six==1.16.0
-tornado==6.4
+tornado==6.4.1
 typing-extensions==4.9.0
 urllib3==1.26.18