minor #2634 [TwigComponent] Add OptionResolver namespace in doc example (ThibaultPelloquin)

This PR was merged into the 2.x branch.

Discussion
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[TwigComponent] Add OptionResolver namespace in doc example

…lver

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| License       | MIT

Just to make the documentation clearer for developers who may not be familiar with using the OptionsResolver component.

Commits
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20928be [TwigComponent] Add use Symfony\Component\OptionsResolver\OptionsResolver

Author: Kocal

src/TwigComponent/doc/index.rst

@@ -498,6 +498,7 @@ If you need to modify/validate data before it's *mounted* on the
 component use a ``PreMount`` hook::
 
     // src/Twig/Components/Alert.php
+    use Symfony\Component\OptionsResolver\OptionsResolver;
     use Symfony\UX\TwigComponent\Attribute\PreMount;
     // ...