Bump enumn from 0.1.11 to 0.1.12 (#1412)

Bumps [enumn](https://github.com/dtolnay/enumn) from 0.1.11 to 0.1.12.
- [Release notes](https://github.com/dtolnay/enumn/releases)
- [Commits](https://github.com/dtolnay/enumn/compare/0.1.11...0.1.12)

---
updated-dependencies:
- dependency-name: enumn
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Bastian Köcher <[email protected]>