Bumps [attrs](https://github.com/python-attrs/attrs) from 21.3.0 to 21.4.0. - [Release notes](https://github.com/python-attrs/attrs/releases) - [Changelog](https://github.com/python-attrs/attrs/blob/main/CHANGELOG.rst) - [Commits](https://github.com/python-attrs/attrs/compare/21.3.0...21.4.0) --- updated-dependencies: - dependency-name: attrs dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>