add submenu page doesn’t display

The fourth parameter in add_submenu_page function is a capability. Try changing it to manage_options so your code looks like this:

add_submenu_page('tictac_admin_menu',
  'Sous menu Opening',
  'Options Opening',
  'manage_options',
  'tictac_scripts_menu',
  'tictac_opening_submenu'

);

Hope it helps