HCP Packer adds bucket-level RBAC

HCP Packer has introduced bucket-level RBAC, allowing users to manage access at the bucket level for enhanced security and permissions control. This feature enables organizations to mitigate security risks by practicing the principle of least privilege. With bucket-level RBAC, developers can create buckets within projects without needing full project access, while admins can assign specific permissions at the bucket level. This improvement allows sensitive golden images to remain protected from unauthorized modifications while giving developers self-service capabilities for agility and efficiency.