Clarify Clean Deployment task metadata process

[stuart23]

Do these backup specs need to be here? Can we leave them out? What happens if the customer doesn't want to have this data saved to an external storage service?

https://github.com/astronomer/docs/blob/f4baac953467dde543ca91edcdf1f91bdbfc72cf/software/configure-deployment.md?plain=1#L268-L281