Fix stop-app in grails cli

[codeconsole]

https://github.com/grails-profiles/base/blob/7.0.x/commands/stop-app.groovy

[codeconsole]

grails-profiles/base#31

[codeconsole]

management-agent.jar was removed after java 1.8 and this code should be removed/refactored

https://github.com/grails-profiles/base/blob/6294515794b8ac8ae4eeb6a3da7ff40e5f132bb8/commands/stop-app.groovy#L31

[codeconsole]

https://github.com/grails-profiles/base/blob/6294515794b8ac8ae4eeb6a3da7ff40e5f132bb8/commands/stop-app.groovy#L76-L98

Perhaps there is a better way to stop the app similar to how quit works

grails-core/grails-shell/src/main/groovy/org/grails/cli/GrailsCli.groovy

Lines 665 to 672 in ab9fdf3

	private void exitInteractiveMode() {
	keepRunning = false
	try {
	GradleAsyncInvoker.POOL.shutdownNow()
	} catch (Throwable e) {
	// ignore
	}
	}