Move CI to newer images. #249

Job	Run time
swift (debug)	1m 29s
xcodebuild (ios, Debug)	7m 20s
swift (release)	1m 35s
xcodebuild (ios, Release)	7m 55s
xcodebuild (macos, Debug)	7m 54s
xcodebuild (macos, Release)	8m 1s
xcodebuild (tvos, Debug)	6m 14s
xcodebuild (tvos, Release)	7m 33s
xcodebuild (visionos, Debug)	8m 1s
xcodebuild (visionos, Release)	9m 47s
xcodebuild (watchos, Debug)	8m 7s
xcodebuild (watchos, Release)	7m 0s
	1h 20m 56s

Provide feedback