Use Latest Delegate for Minipools (RPIP-77)

## Summary Set minipools managed via Smart Node to use the latest delegate and remove supported Smart Node configuration options for setting older delegates. --- ## Rationale The goal is to improve protocol-wide consistency among minipools, enable pDAO approved minipool changes, and remove some technical blockers to future enforcement mechanisms. A non-trivial number of minipools are persistently underperforming, reducing overall rETH yield and harming demand. Reduced rETH demand complicates the protocol’s transition to the Saturn 1 architecture which includes megapools, the RPL fee switch, and alternative protocol funding mechanisms. While support efforts to remediate underperforming node operators are ongoing, the protocol currently lacks an enforcement mechanism since, by default, minipools are not set to use the most recent delegate contract and it is easy for minipool operators to opt out of delegate upgrades. This creates a situation where governance approved protocol logic cannot be universally applied. Currently, only 7% of operators have proactively selected to use the latest delegate and many of those who have not are likely not even aware of this option. This is an unnecessary obstacle that this proposal corrects. Note that this limitation does not apply to megapools, which do not use the same delegate opt-in model. --- ## Outcome if Positive - A Smart Node update will be released which sets minipools managed via Smart Node to use the latest delegate smart contract and removes supported Smart Node configuration options for setting older delegate implementations. - This Smart Node update does not force non-Smart Node users to change delegates and voters should be aware there are ways around this change even for Smart Node users. --- ## Outcome if Negative - Smart Node will remain at its current default settings. --- ## Context - RPIP-77: <https://rpips.rocketpool.net/RPIPs/RPIP-77> - Initial Discussion Thread: <https://dao.rocketpool.net/t/require-minipools-to-use-latest-delegate/3844> - Sentiment Poll Thread: <https://dao.rocketpool.net/t/use-latest-delegate-in-smart-node-sentiment-poll/3868>