chore: cleanup varnish_client service (#4872)

Author: dannyvw

src/Symfony/Bundle/Resources/config/http_cache_purger.xml

@@ -5,8 +5,6 @@
            xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
 
     <services>
-        <!-- TODO: remove this in 3.0 -->
-        <service id="api_platform.http_cache.purger.varnish_client" class="GuzzleHttp\Client" abstract="true" public="false" />
         <service id="api_platform.http_cache.purger.varnish" alias="api_platform.http_cache.purger.varnish.ban" public="false" />
         <service id="api_platform.http_cache.purger.varnish.ban" class="ApiPlatform\HttpCache\VarnishPurger" public="false" />
         <service id="api_platform.http_cache.purger.varnish.xkey" class="ApiPlatform\HttpCache\VarnishXKeyPurger" public="false">

tests/Symfony/Bundle/DependencyInjection/ApiPlatformExtensionTest.php

@@ -836,7 +836,6 @@ public function testHttpCacheConfiguration(): void
             'api_platform.doctrine.listener.http_cache.purge',
 
             // http_cache_tags.xml
-            'api_platform.http_cache.purger.varnish_client',
             'api_platform.http_cache.purger.varnish.xkey',
             'api_platform.http_cache.purger.varnish.ban',
             'api_platform.http_cache.listener.response.add_tags',