Bump mypy from 1.19.1 to 1.20.0

Bumps [mypy](https://github.com/python/mypy) from 1.19.1 to 1.20.0.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.19.1...v1.20.0)

---
updated-dependencies:
- dependency-name: mypy
  dependency-version: 1.20.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pyproject.toml

@@ -65,7 +65,7 @@ optional-dependencies.dev = [
     "freezegun==1.5.5",
     "furo==2025.12.19",
     "interrogate==1.7.0",
-    "mypy[faster-cache]==1.19.1",
+    "mypy[faster-cache]==1.20.0",
     "mypy-strict-kwargs==2026.1.12",
     "prek==0.3.8",
     "pydocstringformatter==0.7.5",