Bump typing-extensions from 3.10.0.2 to 4.0.0 in /docs (#1126)

Bumps [typing-extensions](https://github.com/python/typing) from 3.10.0.2 to 4.0.0.
- [Release notes](https://github.com/python/typing/releases)
- [Changelog](https://github.com/python/typing/blob/master/typing_extensions/CHANGELOG)
- [Commits](python/typing@3.10.0.2...4.0.0)

---
updated-dependencies:
- dependency-name: typing-extensions
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

docs/requirements.txt

@@ -12,7 +12,7 @@ tomlkit==0.7.2
 pygments==2.10.0
 
 # Dependencies of our project:
-typing-extensions==3.10.0.2
+typing-extensions==4.0.0
 mypy==0.910
 pytest==6.2.5
 hypothesis==6.24.2