Update to Paper 1.21.6

sparklypaper-server/minecraft-patches/sources/net/minecraft/server/MinecraftServer.java.patch

@@ -1,14 +1,14 @@
 --- a/net/minecraft/server/MinecraftServer.java
 +++ b/net/minecraft/server/MinecraftServer.java
-@@ -302,6 +_,7 @@
+@@ -303,6 +_,7 @@
      public boolean isIteratingOverLevels = false; // Paper - Throw exception on world create while being ticked
      private final Set<String> pluginsBlockingSleep = new java.util.HashSet<>(); // Paper - API to allow/disallow tick sleeping
      public static final long SERVER_INIT = System.nanoTime(); // Paper - Lag compensation
 +    public final Set<net.minecraft.world.entity.Entity> entitiesWithScheduledTasks = java.util.concurrent.ConcurrentHashMap.newKeySet(); // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run (concurrent because plugins may schedule tasks async)
  
      public static <S extends MinecraftServer> S spin(Function<Thread, S> threadFunction) {
-         AtomicReference<S> atomicReference = new AtomicReference<>();
-@@ -1657,6 +_,18 @@
+         ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry.init(); // Paper - rewrite data converter system
+@@ -1659,6 +_,18 @@
          this.server.getScheduler().mainThreadHeartbeat(); // CraftBukkit
          // Paper start - Folia scheduler API
          ((io.papermc.paper.threadedregions.scheduler.FoliaGlobalRegionScheduler) org.bukkit.Bukkit.getGlobalRegionScheduler()).tick();
@@ -27,7 +27,7 @@
          getAllLevels().forEach(level -> {
              for (final net.minecraft.world.entity.Entity entity : level.getEntities().getAll()) {
                  if (entity.isRemoved()) {
-@@ -1668,6 +_,8 @@
+@@ -1670,6 +_,8 @@
                  }
              }
          });
@@ -36,7 +36,7 @@
          // Paper end - Folia scheduler API
          io.papermc.paper.adventure.providers.ClickCallbackProviderImpl.CALLBACK_MANAGER.handleQueue(this.tickCount); // Paper
          profilerFiller.push("commandFunctions");
-@@ -1719,7 +_,16 @@
+@@ -1721,7 +_,16 @@
              profilerFiller.push("tick");
  
              try {