Scheduling edge functions docs refers to two different keys

# Improve documentation ## Link https://supabase.com/docs/guides/functions/schedule-functions ## Describe the problem I'm confused by the example here, because the vault setup uses the publishable key, but then the cron job uses the anon key. So which is it? Also, are you meant to hard code the values in the first code block or is it meant to read them from somewhere so they're not just there in the SQL in plain text? And where does that code block go? Right above the cron job or somewhere else? ## Describe the improvement The docs should consistently refer to the same key. ## Additional context I'm assuming this page was updated at some point and the maintainer only updated the key that needs to be used in one of the two code blocks.