Bump mypy from 1.8.0 to 1.15.0

Bumps [mypy](https://github.com/python/mypy) from 1.8.0 to 1.15.0.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.8.0...v1.15.0)

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

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

Author: dependabot[bot]

requirements/mypy.txt

@@ -1,3 +1,3 @@
-mypy==1.8.0
+mypy==1.15.0
 mypy-zope==1.0.3
 types-click==7.1.8