MAPG-199 fix issues found by PHPStan

src/Cli/AddUserCommand.php

@@ -10,7 +10,7 @@ use Symfony\Component\Console\Output\OutputInterface;
 
 class AddUserCommand extends Command
 {
-    public function configure()
+    public function configure(): void
     {
         $this->setName('user:add')
             ->setDescription('Adding of user.')