changelog excerpts: New features DCS failsafe mode Citus support Improvements Suppress recurring errors when dropping unknown but active replic

changelog excerpts: New features DCS failsafe mode Citus support Improvements Suppress recurring errors when dropping unknown but active replication slots Keep only latest failed data directory If bootstrap failed Patroni used to rename $PGDATA folder with timestamp suffix. From now on the suffix will be .failed and if such folder exists it is removed before renaming. Improved check of synchronous replication connection