Keep CLI child close handlers alive when killing on quit

apps/studio/src/modules/cli/lib/execute-command.ts

@@ -179,9 +179,10 @@ export function executeCliCommand(
 		eventEmitter.emit( 'data', { data: message } );
 	} );
 
+	// Only kills the child; the `close` handler still runs to settle the
+	// emitter and detach this listener if a prevented quit keeps the app alive.
 	function appQuitHandler() {
 		const pid = child.pid;
-		child.removeAllListeners();
 
 		// `child.kill()` only terminates the forked CLI process; on Windows its php.exe descendants
 		// would orphan and keep their DLLs locked. `taskkill /T` walks the whole tree instead.

packages/common/lib/cli-process.ts

@@ -139,9 +139,10 @@ export function createCliRunner( config: CliRunnerConfig ): CliRunner {
 	const { cliBinary, nodeBinary, execArgv = [ '--experimental-wasm-jspi' ], onError } = config;
 	const liveChildren = new Set< ChildProcess >();
 
+	// Only kills the child; its `close` handler still runs so awaiting callers
+	// see a failure instead of hanging forever.
 	function killChild( child: ChildProcess ): void {
 		const pid = child.pid;
-		child.removeAllListeners();
 
 		// `child.kill()` only terminates the forked CLI process; on Windows its
 		// php.exe descendants would orphan and keep their DLLs locked. `taskkill