private static void installHook() {
		if (hookInstalled) {
			return;
		}
		Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
			@Override
			public void run() {
				notifyHooks();
			}
		}, "Shutdown Hook Registry Notifier"));
		hookInstalled = true;
	}
Remove a shutdown hook previously registered.
Hooks with a higher priority value will run first
@param hook shutdown hook
Ghidra/Framework/Generic/src/main/java/ghidra/framework/ShutdownHookRegistry.java