fixes #14200 - exclude form templates from select2 initialisation
Form templates shouldn't be initialised with select2, as the elements are copied through add_child_node, e.g. when adding a new external user group inside the user group form. add_child_node calls select2 after copying the form instead.
Related issues
Bug #14200: External user groups auth source dropdown menu doesn't open
fixes #14200 - exclude form templates from select2 initialisation
Form templates shouldn't be initialised with select2, as the elements
are copied through add_child_node, e.g. when adding a new external user
group inside the user group form. add_child_node calls select2 after
copying the form instead.