chore: fix OpenAPI spec (baserow#4341)

Author: silvestrid

changelog/entries/unreleased/bug/4339_fix_openapi_spec_for_generate_table_ai_field_value.json

@@ -0,0 +1,9 @@
+{
+    "type": "bug",
+    "message": "Fix OpenAPI spec for generate_table_ai_field_value",
+    "issue_origin": "github",
+    "issue_number": 4339,
+    "domain": "database",
+    "bullet_points": [],
+    "created_at": "2025-11-26"
+}

premium/backend/src/baserow_premium/api/fields/views.py

@@ -79,9 +79,9 @@ class AsyncGenerateAIFieldValuesView(APIView):
             "dynamically constructed prompt configured in the field settings. "
             "\nThis is a **premium** feature."
         ),
-        request=None,
+        request=GenerateAIFieldValueViewSerializer,
         responses={
-            200: str,
+            202: GenerateAIValuesJobType().response_serializer_class,
             400: get_error_schema(
                 [
                     "ERROR_GENERATIVE_AI_DOES_NOT_EXIST",