Use SwiftSyntax prebuilt action in CI #2708

Job	Run time
Build and Test (ubuntu-24.04, https://download.swift.org/development/ubuntu2404/swift-DEVELOPMENT...	13m 7s
format	40s
check-bridgejs-generated	2m 58s
Test BridgeJS against Swift versions (swift:6.3, 603.0.0)	3m 13s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	18m 45s
Build for native target (macos-15, Xcode_26.0.1)	2m 50s
build-examples	28m 42s
Build and Test (ubuntu-24.04, https://download.swift.org/swift-6.3-branch/ubuntu2404/swift-6.3-DE...	13m 42s
prettier	11s
deploy-examples	-1s
	1h 24m 7s

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