[Easy] Fix env type check errors from VLLM_DEBUG_LOG_API_SERVER_RESPONSE (#26742)

Signed-off-by: Jialin Ouyang <Jialin.Ouyang@gmail.com>

vllm/envs.py

@@ -24,6 +24,7 @@ if TYPE_CHECKING:
     CUDA_VISIBLE_DEVICES: str | None = None
     VLLM_ENGINE_ITERATION_TIMEOUT_S: int = 60
     VLLM_API_KEY: str | None = None
+    VLLM_DEBUG_LOG_API_SERVER_RESPONSE: bool = False
     S3_ACCESS_KEY_ID: str | None = None
     S3_SECRET_ACCESS_KEY: str | None = None
     S3_ENDPOINT_URL: str | None = None