Allow empty port in psql schema dump (#47988)

Co-authored-by: Marc-Etienne Barrut <[email protected]>

Author: Arzaroth

src/Illuminate/Database/Schema/PostgresSchemaState.php

@@ -70,7 +70,7 @@ protected function baseVariables(array $config)
 
         return [
             'LARAVEL_LOAD_HOST' => is_array($config['host']) ? $config['host'][0] : $config['host'],
-            'LARAVEL_LOAD_PORT' => $config['port'],
+            'LARAVEL_LOAD_PORT' => $config['port'] ?? '',
             'LARAVEL_LOAD_USER' => $config['username'],
             'PGPASSWORD' => $config['password'],
             'LARAVEL_LOAD_DATABASE' => $config['database'],