minor #2766 [Turbo] Fix Turbo CI (PHPStan & Functional tests) (Kocal)

This PR was merged into the 2.x branch.

Discussion
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[Turbo] Fix Turbo CI (PHPStan & Functional tests)

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| Docs?         | no <!-- required for new features -->
| Issues        | Fix #... <!-- prefix each issue number with "Fix #", no need to create an issue if none exist, explain below instead -->
| License       | MIT

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Looks like the CI for Turbo was broken for a moment... let's fix it :)

Commits
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de6f26f [Turbo] Fix Turbo CI (PHPStan & Functional tests)

Author: Kocal

src/Turbo/src/Bridge/Mercure/Broadcaster.php

@@ -68,6 +68,12 @@ public function broadcast(object $entity, string $action, array $options): void
         $topics = [];
 
         foreach ((array) ($options['topics'] ?? []) as $topic) {
+            // @phpstan-ignore function.alreadyNarrowedType ($topic should always be a string given the PHPDoc... could be removed in 3.x)
+            if (!\is_string($topic)) {
+                $topics[] = $topic;
+                continue;
+            }
+
             if (!str_starts_with($topic, '@=')) {
                 $topics[] = $topic;
                 continue;