Debug flag should apply to single invocation only

[kichristensen]

What does this change

This fixes a regression bug, where the --debug carries over to other invocations of the porter upgrade command.

What issue does it fix

Closes #3240

Notes for the reviewer

Checklist

• Did you write tests?
• Did you write documentation?
• Did you change porter.yaml or a storage document record? Update the corresponding schema file.
• If this is your first pull request, please add your name to the bottom of our Contributors list. Thank you for making Porter better! 🙇‍♀️

[schristoff]

This looks good - I poked around to see if there was a better place to put this but this makes the most sense.