[symfony/twig-bundle] The var name must use snake_case; expected frankenphp_hot_reload

[StellarGlitch]

The newly added section from PR #1526 unfortunately does not meet the Twig coding standards.
Twig CS Fixer reports:

 KO .\templates\base.html.twig
 ------- ------------------------------------------------------------------------------------------------
  ERROR   13   |
          14   |         {% set frankenphpHotReload = app.request.server.get('FRANKENPHP_HOT_RELOAD') %}
          >>   | The var name must use snake_case; expected frankenphp_hot_reload.
          15   |         {% if frankenphpHotReload %}
 ------- ------------------------------------------------------------------------------------------------