Deploy patch - tags issue

[niall-turbitt]

Deployment failing because tags already exist on the endpoint and then we were trying to add tags which already exist.

Try catch which:

1. Checks if the endpoint exists using WorkspaceClient().serving_endpoints.get()
2. If endpoint exists: Deploys WITHOUT tags (to avoid the duplicate key error)
3. If endpoint is new: Deploys WITH tags (so new endpoints still get tagged)