Added psalm configuration and refined source.

src/Manager/Toolbar_Manager.php

@@ -29,6 +29,8 @@ class Toolbar_Manager {
 	 * Render interface and add to the toolbar.
 	 *
 	 * @param \WP_Admin_Bar $wp_admin_bar WordPress core toolbar object.
+	 *
+	 * @psalm-suppress MixedArgument
 	 */
 	public function admin_bar_menu( \WP_Admin_Bar $wp_admin_bar ): void {