Bump websockets from 8.1 to 9.1

Bumps [websockets](https://github.com/aaugustin/websockets) from 8.1 to 9.1.
- [Release notes](https://github.com/aaugustin/websockets/releases)
- [Changelog](https://github.com/aaugustin/websockets/blob/9.1/docs/changelog.rst)
- [Commits](https://github.com/aaugustin/websockets/compare/8.1...9.1)

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

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

requirements.txt

@@ -79,7 +79,7 @@ virtualenv==20.0.27
 virtualenv-clone==0.5.4
 virtualenvwrapper==4.8.4
 Voice==0.1.0
-websockets==8.1
+websockets==9.1
 yarl==1.4.2
 youtube-dl==2020.6.6
 zipp==3.1.0