Use __return_empty_string instead of custom function

includes/blocks/class-sensei-block-quiz-question.php

@@ -22,21 +22,21 @@ public function __construct() {
 		Sensei_Blocks::register_sensei_block(
 			'sensei-lms/quiz-question',
 			[
-				'render_callback' => [ $this, 'render_empty_string' ],
+				'render_callback' => [ $this, '__return_empty_string' ],
 			],
 			Sensei()->assets->src_path( 'blocks/quiz/question-block' )
 		);
 		Sensei_Blocks::register_sensei_block(
 			'sensei-lms/question-description',
 			[
-				'render_callback' => [ $this, 'render_empty_string' ],
+				'render_callback' => [ $this, '__return_empty_string' ],
 			],
 			Sensei()->assets->src_path( 'blocks/quiz/question-description-block' )
 		);
 		Sensei_Blocks::register_sensei_block(
 			'sensei-lms/question-answers',
 			[
-				'render_callback' => [ $this, 'render_empty_string' ],
+				'render_callback' => [ $this, '__return_empty_string' ],
 			],
 			Sensei()->assets->src_path( 'blocks/quiz/question-answers-block' )
 		);
@@ -53,22 +53,8 @@ public function __construct() {
 	 * @return string The block HTML.
 	 */
 	public function render_quiz_question( array $attributes, string $content ): string { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed
-		_deprecated_function( __METHOD__, '$$next-version$$', 'Sensei_Block_Quiz_Question::render_empty_string' );
+		_deprecated_function( __METHOD__, '$$next-version$$', '__return_empty_string' );
 
 		return '';
 	}
-
-	/**
-	 * Renders the block as an empty string.
-	 *
-	 * @since $$next-version$$
-	 *
-	 * @param array  $attributes The block attributes.
-	 * @param string $content    The block content.
-	 *
-	 * @return string The block HTML.
-	 */
-	public function render_empty_string( array $attributes, string $content ): string { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed
-		return '';
-	}
 }