Update NamespaceTEMPORAL_UPDATE_NAMESPACE
Update a Temporal Cloud Namespace specification asynchronously using the latest resource version for optimistic concurrency. WARNING: this full-spec replacement can change retention, regions, capacity, authentication, deletion protection, and high-availability behavior; newly added custom Search Attributes cannot be deleted. Preserve every unchanged field and verify API-key access and deletion protection before calling. Requires Namespace Admin access.