Remove typed function from API reference (#64429)

Co-authored-by: luisherranz <luisherranz@git.wordpress.org>
Co-authored-by: fabiankaegy <fabiankaegy@git.wordpress.org>
Co-authored-by: atachibana <atachibana@git.wordpress.org>

docs/reference-guides/interactivity-api/api-reference.md

@@ -776,7 +776,7 @@ Actions are just regular JavaScript functions. Usually triggered by the `data-wp
 ```ts
 const { state, actions } = store("myPlugin", {
   actions: {
-    selectItem: (id?: number) => {
+    selectItem: ( id ) => {
       const context = getContext();
       // `id` is optional here, so this action can be used in a directive.
       state.selected = id || context.id;