Apple、デベロッパー向けにiOS 15.6 beta 4 (19G5056c)、iPadOS 15.6 beta 4 (19G5056c)、watchOS 8.7 beta 4 (19U5056c)、tvOS 15.6 beta 4 (19M5056c)を配布開始
https://developer.apple.com/news/releases/