WIP: Initial macOS CI, start with swift testing #626

Job	Run time
Java tests (swift:6.1.2 jdk:Corretto os:jammy)	7m 45s
Swift tests (swift:6.1.2 jdk:Corretto os:jammy)	4m 43s
Verify Sample JavaKitSampleApp (swift:6.1.2 jdk:Corretto os:jammy)	3m 41s
Verify Sample JavaProbablyPrime (swift:6.1.2 jdk:Corretto os:jammy)	3m 48s
Verify Sample JavaSieve (swift:6.1.2 jdk:Corretto os:jammy)	57s
macOS tests / Construct Darwin matrix	3s
Verify Sample JavaDependencySampleApp (swift:6.1.2 jdk:Corretto os:jammy)	4m 18s
Verify Sample SwiftKitSampleApp (swift:6.1.2 jdk:Corretto os:jammy)	4m 41s
Verify Sample SwiftAndJavaJarSampleLib (swift:6.1.2 jdk:Corretto os:jammy)	3m 55s
soundness / Documentation check	35s
soundness / Unacceptable language check	3s
soundness / Python lint check	7s
soundness / YAML lint check	4s
soundness / License headers check	5s
soundness / Shell check	31s
soundness / Broken symlinks check	3s
soundness / API breakage check	0s
soundness / Format check	0s
macOS tests / Xcode 16.2	1s
macOS tests / Xcode 26 beta 1	1s
macOS tests / Xcode 16.3	1d 0h 0m 1s
	1d 0h 35m 22s

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