SyncAutoScalerAnn can be removed in the PD and TiKV scaler

[DanielZhangQD]

Feature Request

Is your feature request related to a problem? Please describe:

Describe the feature you'd like:

We have refactored the auto-scaling implementation in v1.2, and the original logic introduced in v1.1.x can be removed, such as the SyncAutoScalerAnn function in the PD and TiKV scaler.
Refer to PR #1801.
Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy:

[mianhk]

/assign