Fix Protocol imports on >=3.10

[FasterSpeeding]

Description

Since typing_extensions is only required on >3.10, attempts to run the latest release on <=3.10 fail if typing_extensions hasn't been installed into the target environment.

Protocol was added to the std typing module in 3.8 so this should only ever need to fallback to typing_extensions for Protocol on 3.7 and some 3.8 alpha releases.

I don't know why your CI is installing typing_extensions before running tests on 3.10 and 3.11.

Before merge

• tox runs successfully
• Docs updated

Before release (if applicable)

• Version updated in pyproject.toml
• Version updated in pre-commit hook example
• Version updated in changelog
• Branch merged
• Tag created and pushed
• Published

[ariebovenberg]

Thanks! I can handle the release from here. It probably didn't trigger any build failure due to typing-extensions being a test dependency 🤔

[ariebovenberg]

@FasterSpeeding release 0.16.3 is now out with your fix 🚀