Add mypy pre-commit hook

Follows recommendations at python/mypy#13916

Author: craigds

.pre-commit-config.yaml

@@ -28,3 +28,11 @@ repos:
       - id: cmake-lint
         args:
           - --suppress-decorations
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v1.13.0
+    hooks:
+      - id: mypy
+        name: Check types with mypy
+        language: system
+        entry: build/venv/bin/mypy
+        pass_filenames: false