Fix new linter error when importing annotationlib

Author: miguelgrinberg

elasticsearch/dsl/document_base.py

@@ -39,7 +39,7 @@
 try:
     import annotationlib
 except ImportError:
-    annotationlib = None
+    annotationlib = None  # type: ignore[assignment, misc]
 
 try:
     from types import UnionType