Support for CRON jobs

**Is your feature request related to a problem? Please describe.**
There is currently no way to run a task on a schedule using Static Web Apps. This is something that Azure Functions have supported for a long time and is a very useful feature.

**Describe the solution you'd like**
It would be great if Static Web Apps supported Cron jobs where you can specify a Cron expression and the path it should trigger, similar to how Vercel does it [https://vercel.com/guides/how-to-setup-cron-jobs-on-vercel#create-or-update-your-vercel.json-file](https://vercel.com/guides/how-to-setup-cron-jobs-on-vercel#create-or-update-your-vercel.json-file).

**Describe alternatives you've considered**
As an alternative, you'd either have to rely on an external sass solution, or use a the "bring-your-own" function app feature I guess?