Restrict @JSClass to structs #1962

Job	Run time
check-bridgejs-generated	2m 47s
Build for native target (macos-15, Xcode_16.4)	3m 0s
build-examples	41m 57s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	17m 6s
Build and Test (ubuntu-24.04, https://download.swift.org/development/ubuntu2404/swift-DEVELOPMENT...	12m 15s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.1-release/ubuntu2204/swift-6.1-R...	14m 8s
format	30s
Build and Test (ubuntu-24.04, https://download.swift.org/swift-6.3-branch/ubuntu2404/swift-6.3-DE...	13m 12s
deploy-examples	0s
	1h 44m 55s

Provide feedback