Bump tornado from 6.4.2 to 6.5.1 in /doc (#309)

Bumps [tornado](https://github.com/tornadoweb/tornado) from 6.4.2 to 6.5.1.
- [Changelog](https://github.com/tornadoweb/tornado/blob/master/docs/releases.rst)
- [Commits](tornadoweb/tornado@v6.4.2...v6.5.1)

---
updated-dependencies:
- dependency-name: tornado
  dependency-version: 6.5.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

doc/requirements.txt

@@ -78,7 +78,7 @@ stack-data==0.6.3 ; python_version >= "3.9" and python_version < "3.15"
 threadpoolctl==3.5.0 ; python_version >= "3.9" and python_version < "3.15"
 tinycss2==1.4.0 ; python_version >= "3.9" and python_version < "3.15"
 tomli==2.2.1 ; python_version >= "3.9" and python_version < "3.15"
-tornado==6.4.2 ; python_version >= "3.9" and python_version < "3.15"
+tornado==6.5.1 ; python_version >= "3.9" and python_version < "3.15"
 traitlets==5.14.3 ; python_version >= "3.9" and python_version < "3.15"
 typing-extensions==4.12.2 ; python_version >= "3.9" and python_version < "3.15"
 tzdata==2025.1 ; python_version >= "3.9" and python_version < "3.15"