Implement `onPageLoad` for playwright #1790

Job	Run time
check-bridgejs-generated	5m 32s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.0.2-release/ubuntu2204/swift-6.0...	4m 35s
format	39s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.1-release/ubuntu2204/swift-6.1-R...	5m 57s
Build for native target (macos-15, Xcode_16.4)	54s
build-examples	10m 41s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	6m 16s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	6m 44s
deploy-examples	0s
	41m 18s

Provide feedback