Bump mypy from 1.14.0 to 1.15.0 in /requirements

Bumps [mypy](https://github.com/python/mypy) from 1.14.0 to 1.15.0.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.14.0...v1.15.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

requirements/dev-requirements.txt

@@ -5,6 +5,6 @@ coverage==7.6.1; python_version>='3.8' and python_version<'3.9'
 coverage==7.6.9; python_version>='3.9'
 # checks
 flake8==7.1.1
-mypy==1.14.0
+mypy==1.15.0
 types-PyYAML==6.0.12.20241221
 types-setuptools==75.6.0.20241223