🚀 Feature Request: Deleting a worker using `custom_domain`, does not delete the edge certificate generated for it

### Describe the solution

I noticed that when we use `custom_domain = true`, a new edge certificate is created for that custom domain. Deleting the worker does not delete that advanced certificate. We are using this for review apps, and so we have lots of custom domains, and this leads to lots of certificates being built up.

No files or tests are named. Start by tracing worker deletion for workers using custom_domain = true, then follow how the associated edge certificate is created and managed. Done means deleting the worker also removes its generated certificate without affecting unrelated certificates.

Written by the indexing model from the issue text.