Bump regex from 1.6.0 to 1.7.1 in /ql

Bumps [regex](https://github.com/rust-lang/regex) from 1.6.0 to 1.7.1.
- [Release notes](https://github.com/rust-lang/regex/releases)
- [Changelog](https://github.com/rust-lang/regex/blob/master/CHANGELOG.md)
- [Commits](rust-lang/regex@1.6.0...1.7.1)

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

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

Author: dependabot[bot]

ql/Cargo.lock

@@ -18,4 +18,4 @@ tracing = "0.1"
 tracing-subscriber = { version = "0.3.3", features = ["env-filter"] }
 rayon = "1.5.0"
 num_cpus = "1.13.0"
-regex = "1.5.5"
+regex = "1.7.1"