Handle unknown scoreboard objectives (PrismarineJS#3191)

* Handle unknown scoreboard objectives

* Fix lint

* Throw as error instead of string

* Use Object.hasOwn instead of in operator

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Co-authored-by: Frej Alexander Nielsen <frej@valoks.com>
Co-authored-by: Romain Beaumont <romain.rom1@gmail.com>

lib/plugins/scoreboard.js

@@ -19,6 +19,10 @@ function inject (bot) {
     }
 
     if (packet.action === 2) {
+      if (!Object.hasOwn(scoreboards, packet.name)) {
+        bot.emit('error', new Error(`Received update for unknown objective ${packet.name}`))
+        return
+      }
       scoreboards[packet.name].setTitle(packet.displayText)
       bot.emit('scoreboardTitleChanged', scoreboards[packet.name])
     }