Fix error in protected environment using unknown deploy attributes

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Closes #6568 (closed)

This MR fixes an issue where using an unknown value with deploy_access_level_attributes causes a failure because the validation cannot map an Unknown value from the types.Set package into the discreet struct for the schema.

This does mean that when an unknown value is passed, we will not be able to validate the config; as a result, I've added a debug level logging statement to that effect to help if someone submits a log with that issue in the future.