br: pd-ctl don't have command "sched"

[RidRisR]

Bug Report

ref tikv/pd#8414

1. Minimal reproduce step (Required)

Run integration test br_shuffle_leader and br_shuffle_region

2. What did you expect to see? (Required)

Test success.

3. What did you see instead (Required)

Test failed because pd-ctl don't have command "sched"

4. What is your TiDB version? (Required)

master

[HuSharp]

/severity minor