MINOR: make type optional in ES Response (#17832)

* MINOR: make type optional in ES Mixin

* make none as default

* pyformat

ingestion/src/metadata/ingestion/ometa/mixins/es_mixin.py

@@ -46,7 +46,10 @@ class HitsModel(BaseModel):
     """Elasticsearch hits model"""
 
     index: Annotated[str, Field(description="Index name", alias="_index")]
-    type: Annotated[str, Field(description="Type of the document", alias="_type")]
+    type: Annotated[
+        Optional[str],
+        Field(default=None, description="Type of the document", alias="_type"),
+    ]
     id: Annotated[str, Field(description="Document ID", alias="_id")]
     score: Annotated[
         Optional[float], Field(description="Score of the document", alias="_score")