community: fix duplicate content (#28003)

Thank you for reading my first PR!

**Description:**
Deduplicate content in AzureSearch vectorstore.
Currently, by default, the content of the retrieval is placed both in
metadata and page_content of a Document.
This PR removes the content from metadata, and leaves it in
page_content.

**Issue:**:
Previously, the content was popped from result before metadata was
populated.
In #25828 , the order was changed which leads to a response with
duplicated content.
This was not the intention of that PR and seems undesirable.

Looking forward to seeing my contribution in the next version!

Cheers, 
Renzo

libs/community/langchain_community/vectorstores/azuresearch.py

@@ -1798,15 +1798,17 @@ def _result_to_document(result: Dict) -> Document:
             fields_metadata = json.loads(result[FIELDS_METADATA])
     else:
         fields_metadata = {
-            key: value for key, value in result.items() if key != FIELDS_CONTENT_VECTOR
+            key: value
+            for key, value in result.items()
+            if key not in [FIELDS_CONTENT_VECTOR, FIELDS_CONTENT]
         }
     # IDs
     if FIELDS_ID in result:
         fields_id = {FIELDS_ID: result.pop(FIELDS_ID)}
     else:
         fields_id = {}
     return Document(
-        page_content=result.pop(FIELDS_CONTENT),
+        page_content=result[FIELDS_CONTENT],
         metadata={
             **fields_id,
             **fields_metadata,