Fix remaining SplObjectStorage deprecation

Author: nicolas-grekas

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -984,7 +984,7 @@ private function registerWorkflowConfiguration(array $config, ContainerBuilder $
                         $guardsConfiguration[$eventName][] = $configuration;
                     }
                     if ($transition['metadata']) {
-                        $transitionsMetadataDefinition->addMethodCall('attach', [
+                        $transitionsMetadataDefinition->addMethodCall('offsetSet', [
                             new Reference($transitionId),
                             $transition['metadata'],
                         ]);
@@ -1004,7 +1004,7 @@ private function registerWorkflowConfiguration(array $config, ContainerBuilder $
                                 $guardsConfiguration[$eventName][] = $configuration;
                             }
                             if ($transition['metadata']) {
-                                $transitionsMetadataDefinition->addMethodCall('attach', [
+                                $transitionsMetadataDefinition->addMethodCall('offsetSet', [
                                     new Reference($transitionId),
                                     $transition['metadata'],
                                 ]);

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTestCase.php

@@ -376,7 +376,7 @@ public function testWorkflows()
         $transitionsMetadata = $metadataStoreDefinition->getArgument(2);
         $this->assertSame(\SplObjectStorage::class, $transitionsMetadata->getClass());
         $transitionsMetadataCall = $transitionsMetadata->getMethodCalls()[0];
-        $this->assertSame('attach', $transitionsMetadataCall[0]);
+        $this->assertSame('offsetSet', $transitionsMetadataCall[0]);
         $params = $transitionsMetadataCall[1];
         $this->assertCount(2, $params);
         $this->assertInstanceOf(Reference::class, $params[0]);