[Bugfix][Core]Fix block table out-of-range issue in priority scheduling (vllm-project#26661)

Signed-off-by: quanliu <18646313696@163.com>

Author: quanliu1991

vllm/v1/core/sched/scheduler.py

@@ -271,6 +271,9 @@ def schedule(self) -> SchedulerOutput:
                     self.running.remove(preempted_req)
                     if preempted_req in scheduled_running_reqs:
                         scheduled_running_reqs.remove(preempted_req)
+                        token_budget += num_scheduled_tokens[preempted_req.request_id]
+                        req_to_new_blocks.pop(preempted_req.request_id)
+                        num_scheduled_tokens.pop(preempted_req.request_id)
                 else:
                     preempted_req = self.running.pop()