Bump yarl from 1.20.1 to 1.21.0

Bumps [yarl](https://github.com/aio-libs/yarl) from 1.20.1 to 1.21.0.
- [Release notes](https://github.com/aio-libs/yarl/releases)
- [Changelog](https://github.com/aio-libs/yarl/blob/master/CHANGES.rst)
- [Commits](https://github.com/aio-libs/yarl/commits/v1.21.0)

---
updated-dependencies:
- dependency-name: yarl
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]