[jobs-cli] remove to_delete from calculate_changes

remove to_delete from calculate_changes and related code.

to_delete was added because we wanted to be able to rename an already running job by just changing the name in load yaml.
The problem with this is that the name is the only unique identifier of a job, so changing the name of a job is programmatically no different from removing an already running job from the yaml and adding a new one.
The way it's currently implemented the algorithm deletes any job that is running but is not in the jobs.yaml file you are trying to load.

Bug: T364204
Signed-off-by: Ndibe Raymond Olisaemeka rolisaemeka-ctr@wikimedia.org