bug #23870 [DI] Use GlobResource for non-tracked directories (vudaltsov)

This PR was merged into the 3.3 branch.

Discussion
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[DI] Use GlobResource for non-tracked directories

| Q             | A
| ------------- | ---
| Branch?       | 3.3
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

I noticed that some of my excluded directories are still tracked by the container and changes to files inside them make it recompile. This brought me to the `$trackContents || is_dir($path)` line introduced in #21505.

Commits
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048eb18 [DI] Use GlobResource for non-tracked directories

Author: nicolas-grekas

DependencyInjection/FrameworkExtension.php

@@ -1346,7 +1346,7 @@ private function registerSerializerConfiguration(array $config, ContainerBuilder
                 $fileRecorder('yml', $file);
             }
 
-            if ($container->fileExists($dir = $dirname.'/Resources/config/serialization')) {
+            if ($container->fileExists($dir = $dirname.'/Resources/config/serialization', '/^$/')) {
                 $this->registerMappingFilesFromDir($dir, $fileRecorder);
             }
         }