Bump pre-commit from 1.20.0 to 1.21.0 (#870)
Bump pre-commit from 1.20.0 to 1.21.0 (#870)

Bumps [pre-commit](https://github.com/pre-commit/pre-commit) from 1.20.0 to 1.21.0.
- [Release notes](https://github.com/pre-commit/pre-commit/releases)
- [Changelog](https://github.com/pre-commit/pre-commit/blob/master/CHANGELOG.md)
- [Commits](https://github.com/pre-commit/pre-commit/compare/v1.20.0...v1.21.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
mozilla/relman-auto-nag,mozilla/bztools,mozilla/relman-auto-nag,mozilla/relman-auto-nag