Placement Decision API for multicluster scheduling

[mikeshng]

Enhancement Description

• One-line enhancement description (can be used as a release note): Introduces the PlacementDecision API, a vendor neutral API that standardizes how multicluster schedulers publish selected clusters for downstream tools such as GitOps and workload controllers.
• Kubernetes Enhancement Proposal: KEP-5313: Placement Decision API for multicluster scheduling #5314
• Discussion Link: https://docs.google.com/document/d/1seK6W_TgSDinogXqEm8bOgFCuKqJ9_qkZdodfkSheUY/edit?usp=sharing
• Primary contact (assignee): @mikeshng
• Responsible SIGs: sig-multicluster
• Enhancement target (which target equals to which milestone):
  • Alpha release target (x.y): TK
  • Beta release target (x.y):
  • Stable release target (x.y):
• Alpha
  • KEP (k/enhancements) update PR(s): TK
  • Code (k/k) update PR(s):
  • Docs (k/website) update PR(s):

/sig multicluster