[Improvements] Merge health check route (#8444)

Signed-off-by: ybyang <ybyang7@iflytek.com>
Co-authored-by: Lianmin Zheng <lianminzheng@gmail.com>
Co-authored-by: Kan Wu <wukanustc@gmail.com>

python/sglang/srt/disaggregation/prefill.py

@@ -460,6 +460,7 @@ class SchedulerDisaggregationPrefillMixin:
 
         # We need to remove the sync in the following function for overlap schedule.
         self.set_next_batch_sampling_info_done(batch)
+        self.maybe_send_health_check_signal()
 
     def process_disagg_prefill_inflight_queue(
         self: Scheduler, rids_to_check: Optional[List[str]] = None