fix: expose disableAuth property on Tenant

[mnahkies]

adds the disableAuth property to the Tenant class, allowing users to distinguish between active and disabled tenants.

ref:

• https://cloud.google.com/identity-platform/docs/reference/rest/v2/projects.tenants#Tenant

[mnahkies]

@lahirumaramba is it possible to get a review of this? It's a fairly minor change, but its somewhat annoying not being able to filter out disabled tenants when scripting over multi-tenant auth projects (currently have to workaround by catching the exception when operations fail on the disabled ones).