chore: upgrade to L9

BREAKING CHANGE: This commit updates the Laravel framework to version 9. Additionally, it also updates outdated and abandoned dependencies in the composer.json file.

The resources/lang directory has also been moved to the repository's root directory.

app/Facades/ContextAwareValidation.php

@@ -25,6 +25,7 @@ use Illuminate\Support\Facades\Facade;
 
 class ContextAwareValidation extends Facade
 {
+    // FIXME: Change to a binding key for L9
     protected static function getFacadeAccessor()
     {
         return 'contextAwareValidator';