Use call to getTempDir instead of direct property access to fix AdminGenerator tests

Author: tobias-93

src/Builder/Generator.php

@@ -74,8 +74,8 @@ public function setTemplateDirs(array $templateDirs): void
      */
     public function __destruct()
     {
-        if ($this->tempDir && is_dir($this->tempDir) && $this->autoRemoveTempDir) {
-            $this->removeDir($this->tempDir);
+        if ($this->getTempDir() && is_dir($this->getTempDir()) && $this->autoRemoveTempDir) {
+            $this->removeDir($this->getTempDir());
         }
     }