redesign / refactor `run` nodes which are succeeding on non-zero exit codes.

Running multiple commands in the same "run" node can hide failures (non zero exit codes) in early commands.

As identified in #30 :
```"the panic returns exit 2, but being wrapped in an echo means action steps exits successfully.```

Example:
https://github.com/GoogleCloudPlatform/cloud-samples-tools/blob/9ae10d71df212f73c5e74f397cffae6008aa3849/actions/steps/affected/action.yaml#L96

This is a tracking issue to consider different ways to improve this pattern so that non-zero exit codes result in the step failing.