[Misc] Fix a config typo in disable_hybrid_kv_cache_manager configuration (#19383)

Signed-off-by: Siyuan Liu <lsiyuan@google.com>

vllm/config.py

@@ -4497,13 +4497,13 @@ class VllmConfig:
             # warning message here and will log it later.
             if not (current_platform.is_cuda() or current_platform.is_rocm()):
                 # Hybrid KV cache manager is not supported on non-GPU platforms.
-                self.disable_hybrid_kv_cache_manager = True
+                self.scheduler_config.disable_hybrid_kv_cache_manager = True
             if self.kv_transfer_config is not None:
                 # Hybrid KV cache manager is not compatible with KV transfer.
-                self.disable_hybrid_kv_cache_manager = True
+                self.scheduler_config.disable_hybrid_kv_cache_manager = True
             if self.kv_events_config is not None:
                 # Hybrid KV cache manager is not compatible with KV events.
-                self.disable_hybrid_kv_cache_manager = True
+                self.scheduler_config.disable_hybrid_kv_cache_manager = True
 
     def update_sizes_for_sequence_parallelism(self,
                                               possible_sizes: list) -> list: