[Codespaces] Environment variables are not propagated to `codespace.config.php` anymore

[R0Wi]

It seems that some changs have been made to the Codespaces environment. For some reason, env vars CODESPACE_NAME and GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN are not readable anymore in codespace.config.php (getenv always returns false).

This leads to a wrong redirect: when opening the Codepace, the user is redirected to "localhost" instead of the codespace subdomain