Bump regex from 1.4.1 to 1.4.4 (#53)

Bumps [regex](https://github.com/rust-lang/regex) from 1.4.1 to 1.4.4.
- [Release notes](https://github.com/rust-lang/regex/releases)
- [Changelog](https://github.com/rust-lang/regex/blob/master/CHANGELOG.md)
- [Commits](rust-lang/regex@1.4.1...1.4.4)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>