e014e5bb61 miner: Enforce murch-zawy rule (BIP54) (Fabian Jahr)
Pull request description:
Opened separate from #35793 as [requested by darosior](https://github.com/bitcoin/bitcoin/pull/35793#discussion_r3704817804). This makes the miner enforce the murch-zawy rule for which #35793 adds the validation part.
A node whose clock is behind the first block of the difficulty period currently reports a mintime below the consensus floor in getblocktemplate and fails to build a valid template for the last block of the period so it can't mine until its clock catches up. This is mostly a theoretical concern on mainnet because it would require a huge system clock misconfiguration. It might be a bigger concern on test networks with volatile hashrates. But generally, I think our miner should be able to create valid templates in any situation.
ACKs for top commit:
kevkevinpal:
crACK [e014e5b](e014e5bb61)
darosior:
ACK e014e5bb61
sedited:
ACK e014e5bb61
Tree-SHA512: 299f83459e92654e028ce1c27470e1dcaae4a58de10687659860cdb425d3af330d3b8da6d8ca8f727c9eaebb2f0a3f3af5185f9daa57e92133435cb80a9e365c
35104a8654