Bump mypy from 1.11.2 to 1.12.1

Bumps [mypy](https://github.com/python/mypy) from 1.11.2 to 1.12.1.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.11.2...v1.12.1)

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

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

requirements/testing.txt

@@ -1,6 +1,6 @@
 -r production.txt
 freezegun==1.5.1
-mypy==1.11.2
+mypy==1.12.1
 pre-commit==4.0.1
 pylint==3.3.1
 pytest==8.3.3