minor #26049 [DI] minor: use a strict comparison in setDecoratedService (dunglas)

This PR was merged into the 2.7 branch.

Discussion
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[DI] minor: use a strict comparison in setDecoratedService

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | no
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md files -->
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

Commits
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f167b50 [DI] minor: use a strict comparision in setDecoratedService

src/Symfony/Component/DependencyInjection/Definition.php

@@ -144,7 +144,7 @@ class Definition
      */
     public function setDecoratedService($id, $renamedId = null)
     {
-        if ($renamedId && $id == $renamedId) {
+        if ($renamedId && $id === $renamedId) {
             throw new \InvalidArgumentException(sprintf('The decorated service inner name for "%s" must be different than the service name itself.', $id));
         }