[Deprecation] Remove deprecated task, seed and MM settings (#30397)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

examples/offline_inference/encoder_decoder_multimodal.py

@@ -77,7 +77,7 @@ def parse_args():
     parser.add_argument(
         "--seed",
         type=int,
-        default=None,
+        default=0,
         help="Set the seed when initializing `vllm.LLM`.",
     )
     return parser.parse_args()