Bump tornado from 6.4.1 to 6.4.2 in /ncli (#6721)

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

Author: dependabot[bot]

ncli/requirements.txt

@@ -79,7 +79,7 @@ stack-data==0.1.4
 terminado==0.12.1
 testpath==0.5.0
 tomli==1.2.3
-tornado==6.4.1
+tornado==6.4.2
 traitlets==5.1.1
 typing_extensions==4.0.1
 wcwidth==0.2.5