Bump tornado from 6.2 to 6.4.2

Bumps [tornado](https://github.com/tornadoweb/tornado) from 6.2 to 6.4.2.
- [Changelog](https://github.com/tornadoweb/tornado/blob/v6.4.2/docs/releases.rst)
- [Commits](tornadoweb/tornado@v6.2.0...v6.4.2)

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

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

requirements.txt

@@ -43,7 +43,7 @@ six==1.16.0
 stack-data==0.6.2
 sympy==1.12.1
 threadpoolctl==3.5.0
-tornado==6.2
+tornado==6.4.2
 tqdm==4.67.0
 traitlets==5.9.0
 tzdata==2024.1