community[patch]: Add missing annotations (#24890)

This PR adds annotations in comunity package.

Annotations are only strictly needed in subclasses of BaseModel for
pydantic 2 compatibility.

This PR adds some unnecessary annotations, but they're not bad to have
regardless for documentation pages.

libs/community/langchain_community/query_constructors/supabase.py

@@ -27,7 +27,7 @@ class SupabaseVectorTranslator(Visitor):
     ]
     """Subset of allowed logical comparators."""
 
-    metadata_column = "metadata"
+    metadata_column: str = "metadata"
 
     def _map_comparator(self, comparator: Comparator) -> str:
         """