[DX] Fix run on custom rector config when no rector.php (#7985)

Author: samsonasik

src/Configuration/ConfigInitializer.php

@@ -20,6 +20,7 @@ public function __construct(
         private array $rectors,
         private InitFilePathsResolver $initFilePathsResolver,
         private SymfonyStyle $symfonyStyle,
+        private RectorConfigsResolver $rectorConfigsResolver,
     ) {
     }
 
@@ -42,6 +43,14 @@ public function createConfig(string $projectDirectory): void
             return;
         }
 
+        $mainConfigFile = $this->rectorConfigsResolver->provide()->getMainConfigFile();
+        if ($mainConfigFile !== null && file_exists($mainConfigFile)) {
+            $this->symfonyStyle->warning(
+                'Register rules or sets in your "' . basename($mainConfigFile) . '" config'
+            );
+            return;
+        }
+
         $response = $this->symfonyStyle->ask(
             'No "' . RectorConfigsResolver::DEFAULT_CONFIG_FILE . '" config found. Should we generate it for you?',
             'yes'