v4: implement onCancel callbacks #2640

Job	Run time
typecheck / typecheck	4m 55s
e2e / 🧪 CLI v3 tests (ubuntu-latest - npm)	2m 32s
e2e / 🧪 CLI v3 tests (ubuntu-latest - pnpm)	2m 10s
e2e / 🧪 CLI v3 tests (windows-latest - npm)	5m 16s
e2e / 🧪 CLI v3 tests (windows-latest - pnpm)	5m 35s
units / 🧪 Unit Tests	13m 35s
	34m 3s

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