⬆️ Bump attrs from 21.2.0 to 21.3.0

Bumps [attrs](https://github.com/python-attrs/attrs) from 21.2.0 to 21.3.0.
- [Release notes](https://github.com/python-attrs/attrs/releases)
- [Changelog](https://github.com/python-attrs/attrs/blob/main/CHANGELOG.rst)
- [Commits](python-attrs/attrs@21.2.0...21.3.0)

---
updated-dependencies:
- dependency-name: attrs
  dependency-type: indirect
  update-type: version-update:semver-minor
...

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