Can we add applyTo to credentials too?

[carolynvs]

Currently, both parameters and outputs support the applyTo field which allows an author to communicate that the paramter/output is only applicable for particular actions. This is helpful especially for required parameters, so that as a user, I don't have to specify a required parameter for actions where it isn't used at all.

At first glance, being able to say "I don't need (rando cloud credentials) to perform the dry-run action" would be very user friendly. It's annoying to have to specify credentials for actions that do not use them just because install needed those credentials.

I would like to understand if applyTo was left off of credentials on purpose or if it was an oversight?

I can see technical / usability challenges around CredentialSets when each action may require a different sets of credentials depending on applyTo. But I am not sure I see any outright problems that would prevent us from adding applyTo to credentials. What do you all think?