Bump tornado from 6.4.1 to 6.4.2 (#45)

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
...

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

requirements.txt

@@ -61,7 +61,7 @@ sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==2.0.0
 sphinxcontrib-serializinghtml==2.0.0
 tinycss2==1.4.0
-tornado==6.4.1
+tornado==6.4.2
 traitlets==5.14.3
 ukkonen==1.0.1
 urllib3==2.2.3