[BUGFIX] Use proper dependency injection in ReferenceIndex test

The Rector modernization incorrectly changed GeneralUtility::makeInstance()
to direct instantiation with 'new', which bypasses TYPO3's dependency
injection container. This causes the ReferenceIndex to fail on both
TYPO3 v12 and v13 because required dependencies are not injected.

Fix: Use GeneralUtility::makeInstance() for TYPO3 v12 compatibility.

Author: CybotTM

Tests/Functional/DataHandling/RteImageSoftReferenceParserTest.php

@@ -28,7 +28,7 @@ public function updateReferenceIndexAddsIndexEntryForImage(): void
 
         $versionInformation = GeneralUtility::makeInstance(Typo3Version::class);
         if ($versionInformation->getMajorVersion() < 13) {
-            (new ReferenceIndex())->updateIndex(false);
+            GeneralUtility::makeInstance(ReferenceIndex::class)->updateIndex(false);
         } else {
             $this->get(ReferenceIndex::class)->updateIndex(false);
         }