Bump parking_lot from 0.12.2 to 0.12.3

Bumps [parking_lot](https://github.com/Amanieu/parking_lot) from 0.12.2 to 0.12.3.
- [Changelog](https://github.com/Amanieu/parking_lot/blob/master/CHANGELOG.md)
- [Commits](Amanieu/parking_lot@0.12.2...0.12.3)

---
updated-dependencies:
- dependency-name: parking_lot
  dependency-type: indirect
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>