Add global in DOC comment, Remove unnecessary is_array check, Update comment about usage of global

Author: b1ink0

plugins/webp-uploads/hooks.php

@@ -785,6 +785,8 @@ function webp_uploads_init(): void {
  * Automatically opt into extra image sizes when generating fallback images.
  *
  * @since n.e.x.t
+ *
+ * @global array $_wp_additional_image_sizes Associative array of additional image sizes.
  */
 function webp_uploads_opt_in_extra_image_sizes(): void {
 	if ( ! webp_uploads_is_fallback_enabled() ) {
@@ -793,11 +795,7 @@ function webp_uploads_opt_in_extra_image_sizes(): void {
 
 	global $_wp_additional_image_sizes;
 
-	if ( ! is_array( $_wp_additional_image_sizes ) ) {
-		return;
-	}
-
-	// NOTE: Modifying global to mimic the "hypothetical" WP core API behavior.
+	// Modify global to mimic the "hypothetical" WP core API behavior via an additional `add_image_size()` parameter.
 
 	if ( isset( $_wp_additional_image_sizes['1536x1536'] ) && ! isset( $_wp_additional_image_sizes['1536x1536']['provide_additional_mime_types'] ) ) {
 		$_wp_additional_image_sizes['1536x1536']['provide_additional_mime_types'] = true; // phpcs:ignore WordPress.WP.GlobalVariablesOverride.Prohibited