[Umbrella] Infrastructure upgrading and enhancement(release-1.18)

[RainbowMango]

Summary:

This issue is used to track the iteration tasks of infrastructure upgrading.

Iteration Tasks:

• Prow bot upgrade
  • Config additional labels to labels plugin, so that labels can be added by /lable command.
    • Reference: Feat: Promote ControllerPriorityQueue to beta karmada#7200 (comment)
  • Introduce new labels for testing PRs. (#5506)
  • Add do-not-merge/invalid-commit-message to tide. (After invalidcommitmsg flags some node.js dependabot commits as invalid kubernetes-sigs/prow#571)
  • Enable cherrypicker external plugin for cherry-pick automation.
    • Consider also enable cherry-pick-approved or cherry-pick-unapproved plugin for label automation
• Adot automatic merge strategy(not sure yet)(#6497)