Bump mypy from 1.4.1 to 1.8.0

Bumps [mypy](https://github.com/python/mypy) from 1.4.1 to 1.8.0.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.4.1...v1.8.0)

---
updated-dependencies:
- dependency-name: mypy
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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