mypy: add slightly more strict config

Author: deltragon

pyproject.toml

@@ -66,3 +66,15 @@ types = [
     "types-psutil==7.0.0.20250218",
     "types-python-xlib==0.33.0.20240407"
 ]
+
+[tool.mypy]
+# catch typos in configuration file
+warn_unused_configs = true
+disallow_any_unimported = true
+#check_untyped_defs = true
+warn_unused_ignores = true
+warn_unreachable = true
+enable_error_code = [
+    "ignore-without-code",
+    "possibly-undefined"
+]