This release has some nice new features, includes many fixes (and many related to the developer API) and some other minor changes.
The complete list of changes can be found below in a less readable format (sorry I was lazy)


Features:
- remove pearls immediately when one dies in a duel (or when the round ends)
- "duel-max-rounds for" /duel (20 default) to customize max rounds for duels
- 'spectator-keep-inside-arena' to force spectators to stay inside arenas
- possibility to decide gamemode for spectators (SURVIVAL by default)
- allow removing broadcast message
- trace debug logging (/sprac trace - not useful for most people unless you want to debug something more complex)
- added api#getLastSelectedEditedKit(Player) in the developer API
- debug log error when cooldown module failed to load
- add api#sendDuelRequest in the developer API
- made some command messages better
- added debug logging to "deleteeditedkits"
- update api (more in fixes section)
- added <is_in_queue> placeholders
- overall better debug logging

Fixes:
- ensure sync when giving spawn items (removed async item giving)
- Use autoReconnect=true by default for SQL databases
- added extra check to make sure the arena is available (for some reason the plugin would sometimes try to start a fight in an arena that was already in use when no other arenas were available - the "hacky" fix is for duels only though)
- fix: add Recordable in the API
- fix: bed break if newer material bed
- fixed blockdisappear in ffa arenas
- fixed lms event duration and arena displayname placeholders
- fix: ignore errors when setting biome
- fix: api#getQueuedKit not returning party queue kit
- fixed BotDuelEndEvent.WinnerType not being included in the API
- fixed RoundStartEvent#getPlayer2 although it was deprecated
- removed use of async inventory close
- fixed error on #forceEnd if reason is null
- check kit type in /queue <kit>
- made ffa fight players thread-safe
- fixed language items not being saved sometimes
- fix: send left-queue before actually left the queue for placeholders to work
- mark CitizensNPC as api class (even though it's kind of a bad decision but may help addon devs
- fixed bedwars materials not always changing
- unobfuscate DefaultCachedBlockChange
- mark multiple fight related things as @APIClass
- do not teleport to duplicate ffa arenas on /ffaarena
- /arena alerts not turning off debug logging
- keep DefaultPlayerStats unobfuscated for legacy reasons
- add short delay when forceEnding a fight due to error
- fixed prevent taking armor off in kit editor
- fixed deleting database keeping data.dat failing
- fixed some errors with kit editor
- error with koth capper 1.20
- made storm-wall-outside-arenas work with performance-mode
- fixed attempting to use long scoreboard lines on 1.13
- offline-player-stats was missing from config.yml, disabled by default
- API: do not obfuscate PlayerStats#CachedStatistic etc
- fix: error with CheckKitItemsHelper.java:54
- possibly fix some data migration, use "unknown" as fallback

Misc:
- refactor: minor refactor
- fix some dependencies and repositories (mainly for development)
- remove old references to /party open
- use HIGHEST priority in bedwars EntityDamageEvent, fixes compatibility with some other plugins
- Improved 1.20 (and other newer version) compatibility