update delete command to delete deployment

[emilol]

As discussed in discord:

It looks like kubectl run by default also creates a Deployment, and so by deleting the Pod itself it does not delete the Deployment, and so it spins up another pod.

Updating the instructions to match the results of the kubectl run command

[dedelala]

this behaviour is specific to older versions of kubectl from before kubernetes/kubernetes#87077

can we change this so it's included as a note after the original instructions?