[8.x] Fix exit code of down/up commands when already down/up

[JaZo]

This will return exit code 0 instead of boolean true. The boolean will be cast to an int resulting in exit code 1, but if the application is already down/up exit code 0 would be desirable.

Targeted to 8.x as discussed in #32199.

Change

$ php artisan down
Application is now in maintenance mode.
$ echo $?
0
$ php artisan down
Application is already down.
$ echo $?
- 1
+ 0

$ php artisan up
Application is now live.
$ echo $?
0
$ php artisan up
Application is already up.
$ echo $?
- 1
+ 0

Context

Our deploymenttool (DeployHQ) performs php artisan down before uploading the changes, but stops if this fails. If the deployment fails later in the process - composer install or a migration might fail - our tool stops and the application is still in maintenance mode. If we fix the error and restart the deployment php artisan down now returns an exit code other than 0 and our tool thinks it failed and stops the deployment. This results in a 'locked' state where we have to manually bring the application back up before we can start a new deployment.