ImportTS: `Promise`-returning TS funcs -> `async` Swift #1867

Job	Run time
Build for native target (macos-15, Xcode_16.4)	58s
check-bridgejs-generated	6m 12s
Build and Test (ubuntu-24.04, https://download.swift.org/development/ubuntu2404/swift-DEVELOPMENT...	5m 1s
build-examples	11m 11s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.0.2-release/ubuntu2204/swift-6.0...	4m 46s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.1-release/ubuntu2204/swift-6.1-R...	5m 3s
Build and Test (ubuntu-24.04, https://download.swift.org/swift-6.3-branch/ubuntu2404/swift-6.3-DE...	5m 1s
format	34s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	5m 2s
deploy-examples	0s
	43m 48s

Provide feedback