feat: Add mypy to pre-commit.

.pre-commit-config.yaml

@@ -1,13 +1,23 @@
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: "v0.9.1"
+    rev: "v0.12.11"
     hooks:
       - id: ruff
       - id: ruff-format
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v5.0.0
+    rev: v6.0.0
     hooks:
       - id: trailing-whitespace
         exclude: ".*\\.md$"
       - id: end-of-file-fixer
       - id: check-added-large-files
+  - repo: local
+    hooks:
+      - id: mypy
+        name: Static type check with mypy
+        entry: uv run mypy leggen leggend --check-untyped-defs
+        files: "^leggen(d)?/.*"
+        language: "system"
+        types: ["python"]
+        always_run: true
+        pass_filenames: false