♻️ Use already existing asset collector

For some reason the AssetCollector instance created (or passed) in the
PageRendererPreProcess constructor was not used, but instead a new
instance was made as part of the addLibrary function.

This commit refactors PageRendererPreProcess::addLibrary to use the
already created AssetCollector.

Classes/Hooks/PageRendererPreProcess.php

@@ -29,16 +29,15 @@ class PageRendererPreProcess
         $plausible = $this->getPlausibleURL();
 
         if (isset($domain) && isset($plausible) && !$this->tsfe->isBackendUserLoggedIn()) {
-            GeneralUtility::makeInstance(AssetCollector::class)
+            $this->assetCollector->addJavaScript(
-                ->addJavaScript(
+                'plausible_analytics',
-                    'plausible_analytics',
+                $plausible . '/js/plausible.js',
-                    $plausible . '/js/plausible.js',
+                [
-                    [
+                    'async' => 'async',
-                        'async' => 'async',
+                    'defer' => 'defer',
-                        'defer' => 'defer',
+                    'data-domain' => $domain
-                        'data-domain' => $domain
+                ],
-                    ],
+            );
-                );
         }
     }