Bump ignore from 0.4.20 to 0.4.21

Bumps [ignore](https://github.com/BurntSushi/ripgrep) from 0.4.20 to 0.4.21.
- [Release notes](https://github.com/BurntSushi/ripgrep/releases)
- [Changelog](https://github.com/BurntSushi/ripgrep/blob/master/CHANGELOG.md)
- [Commits](https://github.com/BurntSushi/ripgrep/commits)

---
updated-dependencies:
- dependency-name: ignore
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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