CI: add type checking (#10997)

* Set up type checking with mypy.

* Make mypy pass.

* Use list() instead of sorted().

plugins/module_utils/mh/base.py

@@ -5,15 +5,17 @@
 
 from __future__ import annotations
 
+import typing as t
+
 from ansible.module_utils.basic import AnsibleModule
 from ansible_collections.community.general.plugins.module_utils.mh.exceptions import ModuleHelperException as _MHE
 from ansible_collections.community.general.plugins.module_utils.mh.deco import module_fails_on_exception
 
 
 class ModuleHelperBase(object):
-    module = None
+    module: dict[str, t.Any] | None = None  # TODO: better spec using t.TypedDict
     ModuleHelperException = _MHE
-    _delegated_to_module = (
+    _delegated_to_module: tuple[str, ...] = (
         'check_mode', 'get_bin_path', 'warn', 'deprecate', 'debug',
     )