`offer_issuer_id` included in offers with (blinded) `offer_paths`

[AndySchroder]

1. Only have private channels (required because of allow creating offers with blinded paths when you have public channels #7713) and no public channels.
2. Create new offer
3. decode the offer
4. Find that offer_issuer_id included in offers with (blinded) offer_paths, revealing your node ID and defeating the purpose of the blinded paths.

https://github.com/lightning/bolts/blob/247e83d528a2a380e533e89f31918d7b0ce6a0c1/12-offer-encoding.md?plain=1#L341 says that "The offer_issuer_id can be omitted for brevity, if offer_paths is set, as each of the final blinded_node_id in the paths can serve as a valid public key for the destination.". It seems to me though that in the spec if offer_paths is set,offer_issuer_id should be omitted for privacy.