Update GameManager.kt

Add GameRule to deactivate advancements announcement

src/main/kotlin/club/mcscrims/speedhg/game/GameManager.kt

@@ -67,6 +67,8 @@ class GameManager(
 				damageBuffer = 0.0
 				damageAmount = 1.0
 			}
+
+			world?.setGameRule( GameRule.ANNOUNCE_ADVANCEMENTS, false )
 		}, 10L )
 	}