figure out how to support monthly devnets

[tessr]

We're planning on moving away from a single long-lived devnet and towards monthly devnets tied to upcoming upgrades. However, the SCR does not handle this nicely today.

Context from George

Context from Mark

if we wanted to use the superchain registry as part of the release candidate devnet flow then it would be a lot more adding chains to the superchain registry, which would make us feel the pain of doing so. If we didn’t use the superchain registry for the transient devnet then the superchain registry flow wouldn’t be tested until testnet.

IMO, we should treat the Superchain registry add chain flow as an upstream dependency for the success of the monthly devnet flow. The other words, the devnet flow can’t be considered easy unless the SCR add chain flow is also easy.

[geoknee]

We would probably want to streamline the process of removing a chain, in fact an entire superchain, from the registry. This could be done with new add-chain (now called ops) commands. We haven't done this kind of thing before, but I don't see any fundamental problems.