Allow update-cache to update from unauthenticated endpoints without an api key

[gerrycampion]

Specifically, this is meant to support the Membership Library 2026.
We need to continue to allow free access to Rules and will likely do this by exposing the rules api endpoint without the need of an api-ke.

In the engine, we will need to allow update-cache to run without an api key and fetch data from any endpoints that don't require an api-key. An information message should be printed to describe this. If any api-key is provided, the full update will proceed as always.

Acceptance Criteria

• Update cache runs without an API key
• Unauthorize request are log
• If an API key is provided the full update will proceed
• An information message is printed when running the restricted update

[JozefAerts]

Hi @gerrycampion Is this the CDISC decision?
There has also been the discussion with Chris and others to e.g. limit the bandwith of monthly usage of the API for non-members, but these would still need to register for the API-key. If that is what will be done, I don't think we need to change anything here.

[gerrycampion]

@JozefAerts We don't have a final decision on this detail yet. This is a placeholder for potential work.