PR13527 backport https://github.com/bitcoin/bitcoin/pull/13527/files
faa24441ec047ec336b86f586016b9d318c1c0ad policy: Remove promiscuousmempoolflags (MarcoFalke)
Pull request description:
It seems odd to clutter validation code with features that can only ever be used for testing (testnet or regtest). Removing that test-only code makes the mempool logic less painful to understand and easier to reason about when changed or refactored in the future.
- promiscuousmempoolflags was originally added for segwit tests (#8149).
- adjusted dersig failure message -> mandatory
- due to large changes in D2120, the feature_cltv.py changes have been massaged into the appropriate place