Remove unneccesary phan error suppression

Signed-off-by: Jack Cherng <jfcherng@gmail.com>

Author: jfcherng

src/Diff.php

@@ -250,7 +250,6 @@ public function render(AbstractRenderer $renderer): string
 
         // the "no difference" situation may happen frequently
         return $this->oldNewComparison === 0
-            /** @phan-suppress-next-line PhanDeprecatedFunction */
             ? $renderer->getResultForIdenticals()
             : $renderer->render();
     }