NFC: BridgeJS: Delegate nested container codegen to generic runtime conformances #2247

Job	Run time
Test BridgeJS against Swift versions (swift:6.2, 602.0.0)	58s
format	36s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.1-release/ubuntu2204/swift-6.1-R...	1m 9s
Build and Test (ubuntu-24.04, https://download.swift.org/development/ubuntu2404/swift-DEVELOPMENT...	56s
Build for native target (macos-15, Xcode_16.4)	1m 11s
check-bridgejs-generated	1m 9s
build-examples	56s
Build and Test (ubuntu-24.04, https://download.swift.org/swift-6.3-branch/ubuntu2404/swift-6.3-DE...	57s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	57s
Test BridgeJS against Swift versions (swift:6.1.2, 601.0.0)	59s
deploy-examples	1s
	9m 49s

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