enh/fix: google pse referer header

backend/open_webui/retrieval/web/google_pse.py

@@ -15,6 +15,7 @@ def search_google_pse(
     query: str,
     count: int,
     filter_list: Optional[list[str]] = None,
+    referer: Optional[str] = None,
 ) -> list[SearchResult]:
     """Search using Google's Programmable Search Engine API and return the results as a list of SearchResult objects.
     Handles pagination for counts greater than 10.
@@ -30,7 +31,11 @@ def search_google_pse(
         list[SearchResult]: A list of SearchResult objects.
     """
     url = "https://www.googleapis.com/customsearch/v1"
+
     headers = {"Content-Type": "application/json"}
+    if referer:
+        headers["Referer"] = referer
+
     all_results = []
     start_index = 1  # Google PSE start parameter is 1-based