chore: merge provisioner key and provisioner permissions (#16628)

Provisioner key permissions were never any different than provisioners.
Merging them for a cleaner permission story until they are required (if
ever) to be seperate.

This removed `ResourceProvisionerKey` from RBAC and just uses the
existing `ResourceProvisioner`.

docs/reference/api/schemas.md

@@ -5121,7 +5121,6 @@ Git clone makes use of this by parsing the URL from: 'Username for "https://gith
 | `organization_member`              |
 | `provisioner_daemon`               |
 | `provisioner_jobs`                 |
-| `provisioner_keys`                 |
 | `replicas`                         |
 | `system`                           |
 | `tailnet_coordinator`              |