Consistently guard restarts against concurrent auto updates (#21016)

packages/cli/src/utils/processUtils.ts

@@ -15,7 +15,16 @@ export const RELAUNCH_EXIT_CODE = 199;
 /**
  * Exits the process with a special code to signal that the parent process should relaunch it.
  */
+let isRelaunching = false;
+
+/** @internal only for testing */
+export function _resetRelaunchStateForTesting(): void {
+  isRelaunching = false;
+}
+
 export async function relaunchApp(): Promise<void> {
+  if (isRelaunching) return;
+  isRelaunching = true;
   await waitForUpdateCompletion();
   await runExitCleanup();
   process.exit(RELAUNCH_EXIT_CODE);