HTML API: Update customizable <select> parsing

src/wp-includes/html-api/class-wp-html-open-elements.php

@@ -280,6 +280,7 @@ public function has_element_in_specific_scope( string $tag_name, $termination_li
 	 * >   - th
 	 * >   - marquee
 	 * >   - object
+	 * >   - select
 	 * >   - template
 	 * >   - MathML mi
 	 * >   - MathML mo
@@ -311,6 +312,7 @@ public function has_element_in_scope( string $tag_name ): bool {
 				'TH',
 				'MARQUEE',
 				'OBJECT',
+				'SELECT',
 				'TEMPLATE',
 
 				'math MI',
@@ -470,12 +472,14 @@ public function has_element_in_table_scope( string $tag_name ): bool {
 	 * @since 6.4.0 Stub implementation (throws).
 	 * @since 6.7.0 Full implementation.
 	 *
-	 * @see https://html.spec.whatwg.org/#has-an-element-in-select-scope
+	 * @deprecated {WP_VERSION} This method is no longer part of the HTML standard.
 	 *
 	 * @param string $tag_name Name of tag to check.
 	 * @return bool Whether the given element is in SELECT scope.
 	 */
 	public function has_element_in_select_scope( string $tag_name ): bool {
+		_deprecated_function( __METHOD__, '{WP_VERSION}' );
+
 		foreach ( $this->walk_up() as $node ) {
 			if ( $node->node_name === $tag_name ) {
 				return true;

src/wp-includes/html-api/class-wp-html-processor-state.php

@@ -208,7 +208,8 @@ class WP_HTML_Processor_State {
 	 *
 	 * @since 6.7.0
 	 *
-	 * @see https://html.spec.whatwg.org/#parsing-main-inselect
+	 * @deprecated {WP_VERSION} The "in select" insertion mode was removed from the standard.
+	 *
 	 * @see WP_HTML_Processor_State::$insertion_mode
 	 *
 	 * @var string
@@ -220,7 +221,8 @@ class WP_HTML_Processor_State {
 	 *
 	 * @since 6.7.0
 	 *
-	 * @see https://html.spec.whatwg.org/#parsing-main-inselectintable
+	 * @deprecated {WP_VERSION} The "in select in table" insertion mode was removed from the standard.
+	 *
 	 * @see WP_HTML_Processor_State::$insertion_mode
 	 *
 	 * @var string