### What this PR does / why we need it?
When loading large models (e.g., 163 shards), weight loading can exceed
the default 600s timeout. Engine startup timeout with the error:
```shell
TimeoutError: Timed out waiting for engines to send initial message on input socket.
```
We should increase the `VLLM_ENGINE_READY_TIMEOUT_S ` to avoid it
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: v0.16.0
- vLLM main:
4034c3d32e
---------
Signed-off-by: wangli <wangli858794774@gmail.com>
1f71da80eb