Revert "[5.8] Make register method in the ServiceProvider as part o…

…f the contract In the laravel/framework#27067 pr was added DeferrableProvider service provider.  This Pr will add pretty the same thing.  In case, if it will be accepted then I will add documentation for this."

This reverts commit f7fc225

HashServiceProvider.php

@@ -4,9 +4,8 @@
 
 use Illuminate\Support\ServiceProvider;
 use Illuminate\Contracts\Support\DeferrableProvider;
-use Illuminate\Contracts\Support\RegistrableProvider;
 
-class HashServiceProvider extends ServiceProvider implements DeferrableProvider, RegistrableProvider
+class HashServiceProvider extends ServiceProvider implements DeferrableProvider
 {
     /**
      * Register the service provider.