Fix: Creating deployments for another repository fails with `Not Found`

[liamoneill]

This PR fixes the action from failing when creating a deployment for another repo then where the workflow is running from.

Error from logs:

Error: HttpError: Not Found
Error: Error creating GitHub deployment: Not Found

This was caused by the createDeploymentStatus request hardcoding the repo & owner from context instead of using the repo that deployment was created under.

I've tested the change in workflows that both create deployments on themselves and other repos and the fix applied to be working as expected.