[CDF-25385] 😁 Use upsert instead of delete - create  (#1810)

# Description

We added support for the CRUD operations for WorkflowTrigger resources
in Toolkit before there was an upsert endpoint. As a workaround, we used
list + delete + create. This PR takes advantage of the new upsert
endpoint instead of the workaround.

## Changelog

- [x] Patch
- [ ] Minor
- [ ] Skip

## cdf

### Fixed

- When deploying a workflow trigger, Toolkit no longer deletes and
recreates it. Instead, the trigger is updated.

## templates

No changes.
