minor #20413 [HttpClient] Testing Using HAR Files - access to container param (Ejamine)

This PR was merged into the 6.4 branch.

Discussion
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[HttpClient] Testing Using HAR Files - access to container param

Testing Using HAR Files/ExternalArticleServiceTest should extend from Symfony\Bundle\FrameworkBundle\Test\KernelTestCase to access the container parameter.
6.4 is the oldest version affected.

Commits
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1c2664f Update http_client.rst

Author: javiereguiluz

http_client.rst

@@ -2248,11 +2248,11 @@ First, use a browser or HTTP client to perform the HTTP request(s) you want to
 test. Then, save that information as a ``.har`` file somewhere in your application::
 
     // ExternalArticleServiceTest.php
-    use PHPUnit\Framework\TestCase;
+    use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
     use Symfony\Component\HttpClient\MockHttpClient;
     use Symfony\Component\HttpClient\Response\MockResponse;
 
-    final class ExternalArticleServiceTest extends TestCase
+    final class ExternalArticleServiceTest extends KernelTestCase
     {
         public function testSubmitData(): void
         {