Fix double annotations for Pylint (#172477)

pylint/plugins/pylint_home_assistant/__init__.py

@@ -8,17 +8,38 @@ any module that defines a ``register(linter)`` function will be loaded.
 import importlib
 import pkgutil
 
+from pylint.checkers import BaseChecker
 from pylint.lint import PyLinter
 
 from pylint_home_assistant import checkers
 
 
 def register(linter: PyLinter) -> None:
-    """Register all Home Assistant checkers."""
+    """Register all Home Assistant checkers which have not been registered yet."""
+    existing_checker_types: set[type] = {
+        type(checker)
+        for checkers_list in linter._checkers.values()  # noqa: SLF001
+        for checker in checkers_list
+    }
     # Auto-discover and register all checker modules under ``checkers/``.
     for module_info in pkgutil.walk_packages(
         checkers.__path__, prefix=f"{checkers.__name__}."
     ):
         module = importlib.import_module(module_info.name)
-        if hasattr(module, "register"):
-            module.register(linter)
+        if not hasattr(module, "register"):
+            continue
+        # Skip modules whose checker class is already registered (worker
+        # re-registration in parallel mode). Only consider checker classes
+        # defined in the module itself, not ones imported from pylint.
+        module_checker_types = {
+            value
+            for value in vars(module).values()
+            if (
+                isinstance(value, type)
+                and issubclass(value, BaseChecker)
+                and value.__module__ == module.__name__
+            )
+        }
+        if module_checker_types and module_checker_types <= existing_checker_types:
+            continue
+        module.register(linter)