Bring back visionOS SwiftPM testing. #245

Job	Run time
xcodebuild (ios, Debug)	18m 10s
swift (debug)	1m 18s
xcodebuild (ios, Release)	9m 4s
swift (release)	1m 13s
xcodebuild (macos, Debug)	4m 29s
xcodebuild (macos, Release)	4m 15s
xcodebuild (tvos, Debug)	11m 1s
xcodebuild (tvos, Release)	6m 31s
xcodebuild (visionos, Debug)	4m 52s
xcodebuild (visionos, Release)	7m 50s
xcodebuild (watchos, Debug)	8m 9s
xcodebuild (watchos, Release)	7m 19s
	1h 24m 11s

Provide feedback