[V1] Get supported tasks from model runner instead of model config (#21585)

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

vllm/pooling_params.py

@@ -1,17 +1,16 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
-from typing import TYPE_CHECKING, Literal, Optional
+from typing import TYPE_CHECKING, Optional
 
 import msgspec
 
 from vllm.sampling_params import RequestOutputKind
+from vllm.tasks import PoolingTask
 
 if TYPE_CHECKING:
     from vllm.config import ModelConfig
 
-PoolingTask = Literal["encode", "embed", "classify", "score"]
-
 
 class PoolingParams(
         msgspec.Struct,