Bump mypy from 1.14.1 to 1.15.0 (#489)

Bumps [mypy](https://github.com/python/mypy) from 1.14.1 to 1.15.0.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.14.1...v1.15.0)

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

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

Author: dependabot[bot]

requirements/lint.txt

@@ -1,5 +1,5 @@
 -r ci.txt
-mypy==1.14.1; implementation_name=="cpython"
+mypy==1.15.0; implementation_name=="cpython"
 pre-commit==4.1.0
 sphinx==8.1.3
 sphinxcontrib-asyncio==0.3.0