Discuss retainStagingDir now that none of the composite actions exist anymore

[TwitchBronBron]

We removed retainStagingDir (and retainStagingFolder) in v4 because the RokuDeploy class doesn't have the complex flows anymore.

We need to discuss whether this should be added back in anywhere (maybe in the exec cli command or something else, or maybe the consuming library should just handle this on their own.