Send Email Auth Hook `site_url` is the Supabase project URL and not the configured SiteUrl

# Bug report - [X] I confirm this is a bug with Supabase, not with my own application. - [X] I confirm I have searched the [Docs](https://docs.supabase.com), GitHub [Discussions](https://github.com/supabase/supabase/discussions), and [Discord](https://discord.supabase.com). ## Describe the bug Using the beta "Auth Hooks" feature, when I receive the hook the, `email_data.site_url` property contains the supabase project url, which is used as the root of the {{ .ConfirmationUrl }} . This is inconsistent with {{ .SiteUrl }} that is normally populated in templated (which is the configured application url, not the Supabase Project Url. ## To Reproduce Steps to reproduce the behavior, please provide code snippets or a repository: 1. Set up a Send Email Webhook as described in: https://supabase.com/docs/guides/auth/auth-hooks/send-email-hook 2. Log the payload ## Expected behavior `email_data.site_url` should have the value that {{ .SiteUrl }} is populated with (aka. the value set in config.toml `auth.site_url`