[mypy] Enable following imports for entrypoints (#7248)

Co-authored-by: Woosuk Kwon <woosuk.kwon@berkeley.edu>
Co-authored-by: Fei <dfdfcai4@gmail.com>

format.sh

@@ -102,7 +102,6 @@ mypy vllm/attention --follow-imports skip
 mypy vllm/core --follow-imports skip
 mypy vllm/distributed --follow-imports skip
 mypy vllm/engine  --follow-imports skip
-mypy vllm/entrypoints --follow-imports skip
 mypy vllm/executor --follow-imports skip
 mypy vllm/lora --follow-imports skip
 mypy vllm/model_executor  --follow-imports skip