minor #21642 Fix mention of CompilerPassInterface support for bundles (MatTheCat)

This PR was merged into the 6.4 branch.

Discussion
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 Fix mention of `CompilerPassInterface` support for bundles

Following #20365 (comment)

Commits
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d4bfcb2 Fix mention of `CompilerPassInterface` support for bundles

Author: javiereguiluz

service_container/compiler_passes.rst

@@ -67,52 +67,55 @@ method of the application kernel::
 Working with Compiler Passes in Bundles
 ---------------------------------------
 
-If your compiler pass is relatively small, you can add it directly in the main
-bundle class. To do so, make your bundle implement the
-:class:`Symfony\\Component\\DependencyInjection\\Compiler\\CompilerPassInterface`
-and place the compiler pass code inside the ``process()`` method of the main
-bundle class::
+:doc:`Bundles </bundles>` can define compiler passes in the ``build()`` method of
+the main bundle class (this is not needed when implementing the ``process()``
+method in the extension)::
 
     // src/MyBundle/MyBundle.php
     namespace App\MyBundle;
 
     use App\DependencyInjection\Compiler\CustomPass;
-    use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
     use Symfony\Component\DependencyInjection\ContainerBuilder;
     use Symfony\Component\HttpKernel\Bundle\AbstractBundle;
 
-    class MyBundle extends AbstractBundle implements CompilerPassInterface
+    class MyBundle extends AbstractBundle
     {
-        public function process(ContainerBuilder $container): void
+        public function build(ContainerBuilder $container): void
         {
-            // in this method you can manipulate the service container:
-            // for example, changing some container service:
-            $container->getDefinition('app.some_private_service')->setPublic(true);
-
-            // or processing tagged services:
-            foreach ($container->findTaggedServiceIds('some_tag') as $id => $tags) {
-                // ...
-            }
+            $container->addCompilerPass(new CustomPass());
         }
     }
 
-Alternatively, when using :ref:`separate compiler pass classes <components-di-separate-compiler-passes>`,
-bundles can enable them in the ``build()`` method of their main bundle class::
+If your compiler pass is relatively small, you can make the main bundle class implements
+:class:`Symfony\\Component\\DependencyInjection\\Compiler\\CompilerPassInterface` so that
+it can add itself::
 
     // src/MyBundle/MyBundle.php
     namespace App\MyBundle;
 
     use App\DependencyInjection\Compiler\CustomPass;
+    use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
     use Symfony\Component\DependencyInjection\ContainerBuilder;
     use Symfony\Component\HttpKernel\Bundle\AbstractBundle;
 
-    class MyBundle extends AbstractBundle
+    class MyBundle extends AbstractBundle implements CompilerPassInterface
     {
+
         public function build(ContainerBuilder $container): void
         {
-            parent::build($container);
+            $container->addCompilerPass($this);
+        }
 
-            $container->addCompilerPass(new CustomPass());
+        public function process(ContainerBuilder $container): void
+        {
+            // in this method you can manipulate the service container:
+            // for example, changing some container service:
+            $container->getDefinition('app.some_private_service')->setPublic(true);
+
+            // or processing tagged services:
+            foreach ($container->findTaggedServiceIds('some_tag') as $id => $tags) {
+                // ...
+            }
         }
     }