Update importlib_metadata to 3.4.0

[pyup-bot]

This PR updates importlib_metadata from 3.3.0 to 3.4.0.

Changelog

3.4.0

======

* 10: Project now declares itself as being typed.
* 272: Additional performance enhancements to distribution
discovery.
* 111: For PyPA projects, add test ensuring that
``MetadataPathFinder._search_paths`` honors the needed
interface. Method is still private.

Links

• PyPI: https://pypi.org/project/importlib-metadata
• Changelog: https://pyup.io/changelogs/importlib-metadata/
• Repo: https://github.com/python/importlib_metadata

[duckinator]

bors r+

[bors]

Build succeeded:

• CI success