Update MemoryDrawing.php

Author: oleibman

src/PhpSpreadsheet/Worksheet/MemoryDrawing.php

@@ -101,10 +101,8 @@ private function cloneResource(): void
             // If the image has transparency...
             $transparent = imagecolortransparent($this->imageResource);
             if ($transparent >= 0) {
+                // Starting with Php8.0, next function throws rather than return false
                 $rgb = imagecolorsforindex($this->imageResource, $transparent);
-                if (empty($rgb)) {
-                    throw new Exception('Could not get image colors');
-                }
 
                 imagesavealpha($clone, true);
                 $color = imagecolorallocatealpha($clone, $rgb['red'], $rgb['green'], $rgb['blue'], $rgb['alpha']);