Warn when provided variables are unused

[YrrepNoj]

When deploying (or creating) a Zarf package, users are able to set variables via the --set flag. If the variable a user is trying to set is not used by the package, a warning should be logged when the user gets to the confirmation dialog.

When I ran the command zarf package deploy {PACKAGE} --set=ENABLE_GPU=true I got the following result.
I almost missed that the ENABLE_GPUS variable was still values because I misspelled the value when typing the command.

Describe the solution you'd like

When a variable is provided via the --set flag. I would like a warning if the variable did not actually exist in the config.

Describe alternatives you've considered

Variables that are provided via the zarf-config.yaml might be the exception to this request since. Unsure how the team wants handle that.