Editor: Remove deprecated callable in WP_Style_Engine class.

Resolves a `Use of "static" in callables is deprecated` notice in = PHP 8.2 and mark `WP_Style_Engine` as a `final` class that will not be extended.

Follow-up to [54156].

Props ramonopoly, jrf, andrewserong.
See #56467.

git-svn-id: https://develop.svn.wordpress.org/trunk@54357 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/style-engine/class-wp-style-engine.php

@@ -14,13 +14,14 @@
  *
  * The Style Engine aims to provide a consistent API for rendering styling for blocks across both client-side and server-side applications.
  *
+ * This class is final and should not be extended.
  * This class is for internal Core usage and is not supposed to be used by extenders (plugins and/or themes).
  * This is a low-level API that may need to do breaking changes. Please, use wp_style_engine_get_styles instead.
  *
  * @access private
  * @since 6.1.0
  */
-class WP_Style_Engine {
+final class WP_Style_Engine {
 	/**
 	 * Style definitions that contain the instructions to
 	 * parse/output valid Gutenberg styles from a block's attributes.
@@ -107,28 +108,28 @@ class WP_Style_Engine {
 				'path'          => array( 'border', 'width' ),
 			),
 			'top'    => array(
-				'value_func' => 'static::get_individual_property_css_declarations',
+				'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
 				'path'       => array( 'border', 'top' ),
 				'css_vars'   => array(
 					'color' => '--wp--preset--color--$slug',
 				),
 			),
 			'right'  => array(
-				'value_func' => 'static::get_individual_property_css_declarations',
+				'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
 				'path'       => array( 'border', 'right' ),
 				'css_vars'   => array(
 					'color' => '--wp--preset--color--$slug',
 				),
 			),
 			'bottom' => array(
-				'value_func' => 'static::get_individual_property_css_declarations',
+				'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
 				'path'       => array( 'border', 'bottom' ),
 				'css_vars'   => array(
 					'color' => '--wp--preset--color--$slug',
 				),
 			),
 			'left'   => array(
-				'value_func' => 'static::get_individual_property_css_declarations',
+				'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
 				'path'       => array( 'border', 'left' ),
 				'css_vars'   => array(
 					'color' => '--wp--preset--color--$slug',