Here I am adding a discv5 nodes source into the p2p dial iterator. It's
an improved version of #29533.
Unlike discv4, the discv5 random nodes iterator will always provide full
ENRs. This means we can apply filtering to the results and will only try
dialing nodes which explictly opt into the eth protocol with a matching
chain.
I have also removed the dial iterator from snap. We don't have an
official DNS list for snap anymore, and I doubt anyone else is running
one. While we could potentially filter for snap on discv5, there will be
very few nodes announcing it, and the extra iterator would just stall
the dialer.
---------
Co-authored-by: lightclient <lightclient@protonmail.com>
6eb42a6b4f