chore(deps): update rust crate regex to v1.12.3

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
regex	workspace.dependencies	patch	1.12.2 → 1.12.3

---

Release Notes

rust-lang/regex (regex)

v1.12.3

===================
This release excludes some unnecessary things from the archive published to
crates.io. Specifically, fuzzing data and various shell scripts are now
excluded. If you run into problems, please file an issue.

Improvements:

• #​1319:
  Switch from a Cargo exclude list to an include list, and exclude some
  unnecessary stuff.

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/shuf/shuf-reservoir (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/sort/sort-stale-thread-mem (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)