use Folia world on Folia servers

bukkit/src/main/java/me/caseload/knockbacksync/player/BukkitPlayer.java

@@ -5,6 +5,9 @@ import com.github.retrooper.packetevents.manager.server.ServerVersion;
 import com.github.retrooper.packetevents.protocol.player.User;
 import com.github.retrooper.packetevents.protocol.world.BoundingBox;
 import com.github.retrooper.packetevents.util.Vector3d;
+import me.caseload.knockbacksync.Base;
+import me.caseload.knockbacksync.Platform;
+import me.caseload.knockbacksync.world.FoliaWorld;
 import me.caseload.knockbacksync.world.PlatformWorld;
 import me.caseload.knockbacksync.world.SpigotWorld;
 import org.bukkit.Bukkit;
@@ -135,7 +138,7 @@ public class BukkitPlayer implements PlatformPlayer {
 
     @Override
     public PlatformWorld getWorld() {
-        return new SpigotWorld(bukkitPlayer.getWorld());
+        return Base.INSTANCE.getPlatform() == Platform.FOLIA ? new FoliaWorld(bukkitPlayer.getWorld()) : new SpigotWorld(bukkitPlayer.getWorld());
     }
 
     @Override

bukkit/src/main/java/me/caseload/knockbacksync/world/FoliaWorld.java

@@ -54,6 +54,7 @@ public class FoliaWorld extends SpigotWorld {
         Location location = new Location(super.world, start.getX(), start.getY(), start.getZ());
         CompletableFuture<RayTraceResult> future = new CompletableFuture<>();
 
+        // Yes this code is bad; I know it's bad. We did not design this plugin around Folia, too bad!
         scheduler.execute(plugin, location, () -> {
                 // Existing 1.13+ code using world.rayTraceBlocks
                 Vector startVec = new Vector(start.getX(), start.getY(), start.getZ());