Error in BlockManager.py

[Along-whu]

I think when block.reset()，ref_count should be 1，but the code is 0.

[Orillas]

I think so.Also in nano-vllm repo, the ref_count of block_reset() is 1. https://github.com/GeeeekExplorer/nano-vllm/blob/main/nanovllm/engine/block_manager.py