Portal loop CI testing against its genesis.json

[thehowl]

I don't think this one hit the mark: #2064

What we need is a CI check that downloads the current portal loop genesis.json and makes sure that no transactions that should succeed (ie. succeed in the current portal loop execution) start failing, were the PR to be merged.

[moul]

We won't achieve a green CI with a breaking change, and we don't want to block such changes.

However, we do want to address the portal loop, which is a separate issue. Instead of implementing a CI check in the main repo for each PR, we should set up monitoring to easily notify us and provide a clear list of failing transactions on the production instances. This way, we can quickly identify and resolve issues in the history.

See #2867