bug #258 Fix Symfony 8.1 DependencyInjection deprecation warning (30Sana)

This PR was squashed before being merged into the 2.x branch.

Discussion
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Fix Symfony 8.1 DependencyInjection deprecation warning

| Q             | A         |
| ------------- | --------- |
| Bug fix?      | no        |
| New feature?  | no        |
| Deprecations? | no        |
| Issues        | Fix #257  |
| License       | MIT       |

Fix Symfony 8.1 DependencyInjection deprecation warning

Replaces the deprecated `Symfony\Component\HttpKernel\DependencyInjection\Extension` with `Symfony\Component\DependencyInjection\Extension\Extension` as required since Symfony 8.1.

Commits
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2bee63b Fix Symfony 8.1 DependencyInjection deprecation warning

Author: Kocal

src/DependencyInjection/WebpackEncoreExtension.php

@@ -18,7 +18,7 @@
 use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Loader\PhpFileLoader;
 use Symfony\Component\DependencyInjection\Reference;
-use Symfony\Component\HttpKernel\DependencyInjection\Extension;
+use Symfony\Component\DependencyInjection\Extension\Extension;
 use Symfony\Component\WebLink\EventListener\AddLinkHeaderListener;
 use Symfony\WebpackEncoreBundle\Asset\EntrypointLookup;
 use Symfony\WebpackEncoreBundle\Asset\EntrypointLookupInterface;