Code review discussion here: https://github.com/bitcoin/bitcoin/pull/5286
Released in #Bitcoin v26.0 here: https://bitcoincore.org/en/releases/26.0/
Flavian: "The maximum size for OP_RETURN outputs used to be 80 bytes, then got changed to 40 bytes to be on the safe side. We have now been running with 40 bytes for about 9 months, and nothing catastrophic happened to the Blockchain, so I am proposing to increase it back to 80 bytes."
Luke: "Don't-care-ACK once tests are fixed." < acknowledged
