build(deps-dev): bump mypy from 1.19.1 to 1.20.1

Bumps [mypy](https://github.com/python/mypy) from 1.19.1 to 1.20.1.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.19.1...v1.20.1)

---
updated-dependencies:
- dependency-name: mypy
  dependency-version: 1.20.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pyproject.toml

@@ -11,7 +11,7 @@ dependencies = [
 
 [dependency-groups]
 dev = [
-    "mypy>=1.19.1,<2.0.0",
+    "mypy>=1.20.1,<2.0.0",
     "pre-commit>=4.5.1,<5.0.0",
     "pytest>=9.0.2,<10.0.0",
     "ruff>=0.15.2",