refactor: use self instead of parent class

Author: JaZo

src/Commands/ElasticsearchCreateIndex.php

@@ -32,6 +32,6 @@ public function handle(Client $client): int
 
         $this->info(sprintf('Index "%s" created', $index));
 
-        return Command::SUCCESS;
+        return self::SUCCESS;
     }
 }

src/Commands/ElasticsearchDeleteIndex.php

@@ -30,6 +30,6 @@ public function handle(Client $client): int
 
         $this->info(sprintf('Index "%s" deleted', $index));
 
-        return Command::SUCCESS;
+        return self::SUCCESS;
     }
 }

src/Commands/ElasticsearchRefreshIndex.php

@@ -29,6 +29,6 @@ public function handle(): int
 
         $this->info(sprintf('Dispatched %d index jobs', $models->count()));
 
-        return Command::SUCCESS;
+        return self::SUCCESS;
     }
 }