How to Automate Adding Service Providers on Laravel?

So according to this answer the only way to add service providers is to first run composer update and composer install.

This becomes a problem in terms of automation, as the service provider has already been added to config/app.php in the code repo.

'providers' => [
    ....
    App\Providers\RouteServiceProvider::class,

    /** Forum **/
    'Riari\Forum\ForumServiceProvider',
    'Riari\Forum\Frontend\ForumFrontendServiceProvider',

],

So running composer update and composer install fails with:

[RuntimeException] Error Output: PHP Fatal error: Class 'Riari\Forum\Frontend\ForumFrontendServiceProvider' not found in /repo/myshares/myshares/bootstrap/cache/compiled.php on line 6892

As far as I can see the only way is to run composer update first and then manually add to config/app.php

via Chebli Mohamed