bug symfony#58113 [DependencyInjection] Fix bug on windows, memory exhausted on cache clear, impossible to install new project (eltharin)

This PR was merged into the 7.2 branch.

Discussion
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[DependencyInjection] Fix bug on windows, memory exhausted on cache clear, impossible to install new project

| Q             | A
| ------------- | ---
| Branch?       | 7.2
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Issues        | Fix
| License       | MIT

Since symfony#57948 on windows, I can't make a cache clear with a fatal error form memory exhausted or install a new symfony app.
Xdebug saw an infinite loop.

Correction with DIRECTORY_SEPARATOR constant instead /

Commits
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89b4c87 bug correction

Author: nicolas-grekas

src/Symfony/Component/DependencyInjection/ContainerBuilder.php

@@ -1752,9 +1752,9 @@ private function inVendors(string $path): bool
 
         foreach ($this->vendors as $vendor) {
             if (\in_array($path[\strlen($vendor)] ?? '', ['/', \DIRECTORY_SEPARATOR], true) && str_starts_with($path, $vendor)) {
-                $this->pathsInVendor[$vendor.'/composer'] = false;
-                $this->addResource(new FileResource($vendor.'/composer/installed.json'));
-                $this->pathsInVendor[$vendor.'/composer'] = true;
+                $this->pathsInVendor[$vendor.\DIRECTORY_SEPARATOR.'composer'] = false;
+                $this->addResource(new FileResource($vendor.\DIRECTORY_SEPARATOR.'composer'.\DIRECTORY_SEPARATOR.'installed.json'));
+                $this->pathsInVendor[$vendor.\DIRECTORY_SEPARATOR.'composer'] = true;
 
                 return $this->pathsInVendor[$path] = true;
             }