Bump frozenlist from 1.5.0 to 1.6.0

Bumps [frozenlist](https://github.com/aio-libs/frozenlist) from 1.5.0 to 1.6.0.
- [Release notes](https://github.com/aio-libs/frozenlist/releases)
- [Changelog](https://github.com/aio-libs/frozenlist/blob/master/CHANGES.rst)
- [Commits](aio-libs/frozenlist@v1.5.0...v1.6.0)

---
updated-dependencies:
- dependency-name: frozenlist
  dependency-version: 1.6.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]