[13.x] schedule:pause command should error when its disabled

[jackbayliss]

This will save many future generations trying to resume it in my app when its disabled, which saves them reading my AppServiceProvider hieroglyphics

This follows the exact same behaviour as the queue PauseCommand

framework/src/Illuminate/Queue/Console/PauseCommand.php

Line 40 in 42b494e

$this->components->error('Queue pausing is currently disabled.');

TLDR, think of the juniors man

[jackbayliss]

Err, testDimensionsWithCustomImageSizeMethod is failing. I'll look at it seperately.. but not related to this PR.