bug #61111 [Translation] fix support of TranslatableInterface in IdentityTranslator (VincentLanglet)

This PR was squashed before being merged into the 6.4 branch.

Discussion
----------

[Translation] fix support of `TranslatableInterface` in `IdentityTranslator`

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | yes
| New feature?  | no <!-- if yes, also update src/**/CHANGELOG.md -->
| Deprecations? | no <!-- if yes, also update UPGRADE-*.md and src/**/CHANGELOG.md -->
| Issues        | Fix #... <!-- prefix each issue number with "Fix #"; no need to create an issue if none exists, explain below -->
| License       | MIT

Commits
-------

92ae810d730 [Translation] fix support of `TranslatableInterface` in `IdentityTranslator`

Author: nicolas-grekas

Tests/Extension/Fixtures/StubTranslator.php

@@ -11,12 +11,19 @@
 
 namespace Symfony\Bridge\Twig\Tests\Extension\Fixtures;
 
+use Symfony\Contracts\Translation\TranslatableInterface;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
 class StubTranslator implements TranslatorInterface
 {
     public function trans($id, array $parameters = [], $domain = null, $locale = null): string
     {
+        foreach ($parameters as $k => $v) {
+            if ($v instanceof TranslatableInterface) {
+                $parameters[$k] = $v->trans($this, $locale);
+            }
+        }
+
         return '[trans]'.strtr($id, $parameters).'[/trans]';
     }