Update GitHub Actions Deployment so others can push

Howdy Ketch Buds!

For those wanting to contribute in their own branch, looks like in the GHAS Deployment Config pushes
to an internal Shipa Repo. Could we move this to something generic or configurable in the GHAS?

https://github.com/theketchio/ketch/blob/main/.github/workflows/deploy.yaml#L36-L42

Stay bold!