RTC: Add cap check for single taxonomy term entities (#75708)

Co-authored-by: chriszarate <czarate@git.wordpress.org>
Co-authored-by: ingeniumed <ingeniumed@git.wordpress.org>

Author: 3 people

backport-changelog/7.0/10894.md

@@ -3,3 +3,4 @@ https://github.com/WordPress/wordpress-develop/pull/10894
 * https://github.com/WordPress/gutenberg/pull/75366
 * https://github.com/WordPress/gutenberg/pull/75681
 * https://github.com/WordPress/gutenberg/pull/75682
+* https://github.com/WordPress/gutenberg/pull/75708

lib/compat/wordpress-7.0/class-wp-http-polling-sync-server.php

@@ -275,6 +275,12 @@ private function can_user_sync_entity_type( string $entity_kind, string $entity_
 				return current_user_can( 'edit_post', absint( $object_id ) );
 			}
 
+			// Handle single taxonomy term entities with a defined object ID.
+			if ( 'taxonomy' === $entity_kind && is_numeric( $object_id ) ) {
+				$taxonomy = get_taxonomy( $entity_name );
+				return isset( $taxonomy->cap->assign_terms ) && current_user_can( $taxonomy->cap->assign_terms );
+			}
+
 			// All of the remaining checks are for collections. If an object ID is
 			// provided, reject the request.
 			if ( null !== $object_id ) {