build(deps): 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]>

Cargo.toml

@@ -19,7 +19,7 @@ filetime_creation = "0.1"
 flate2 = { version = "1.0.28", default-features = false }
 fs-err = "2.11.0"
 gzp = { version = "0.11.3", default-features = false, features = ["snappy_default"] }
-ignore = "0.4.20"
+ignore = "0.4.21"
 libc = "0.2.150"
 linked-hash-map = "0.5.6"
 lz4_flex = "0.11.1"