chore: restore gate annotations lost in rebase and align the spliced ImageResponse schema with the CI regeneration

The rebase onto ff2718b dropped the ANN201/BLE001 suppressions from the
variation handler (both back with their reasons), and the hand-spliced
ImageResponse fragment still carried the wider quality enum and the free-
form size branch that the Linux regeneration does not produce - both now
match the exact hunks the check prints.

litellm/proxy/_lazy_openapi_snapshot.json

@@ -22693,9 +22693,7 @@
                   "enum": [
                     "low",
                     "medium",
-                    "high",
-                    "xhigh",
-                    "max"
+                    "high"
                   ],
                   "type": "string"
                 },
@@ -22707,9 +22705,6 @@
             },
             "size": {
               "anyOf": [
-                {
-                  "type": "string"
-                },
                 {
                   "enum": [
                     "1024x1024",
@@ -22717,9 +22712,6 @@
                     "1536x1024"
                   ],
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "title": "Size"

litellm/proxy/image_endpoints/endpoints.py

@@ -407,7 +407,7 @@ async def image_edit_api(
     openapi_extra=dict[str, object](_IMAGE_VARIATION_OPENAPI_EXTRA),
     response_class=ORJSONResponse,
 )  # azure compatible endpoint
-async def image_variation_api(
+async def image_variation_api(  # noqa: ANN201  # response type mirrors image_edit_api (provider-dependent)
     request: Request,
     fastapi_response: Response,
     user_api_key_dict: UserAPIKeyAuth = Depends(user_api_key_auth),  # noqa: B008  # FastAPI dependency injection
@@ -474,7 +474,7 @@ async def image_variation_api(
             user_api_base=user_api_base,
             version=version,
         )
-    except Exception as e:
+    except Exception as e:  # noqa: BLE001  # provider-agnostic error surfacing mirrors image_edit_api
         raise await processor.handle_llm_api_exception(
             e=e,
             user_api_key_dict=user_api_key_dict,