[V1][Minor] Remove outdated comment (#12968)

Signed-off-by: Woosuk Kwon <woosuk.kwon@berkeley.edu>

vllm/v1/core/kv_cache_manager.py

@@ -205,8 +205,6 @@ class KVCacheManager:
                 # Should not exceed the maximum number of blocks per request.
                 # This is especially because the block table has the shape
                 # [..., max_num_blocks_per_req].
-                # TODO(woosuk): Check and reject requests if
-                # num_prompt_tokens + max_tokens > max_model_len.
                 self.max_num_blocks_per_req - len(req_blocks),
             )
             assert num_new_blocks > 0