Do not submit profile lookups to worldgen threads

They block. On network I/O.

If enough tasks are submitted the server will eventually stall
out due to a sync load, as the worldgen threads will be
stalling on profile lookups.

paper-server/src/main/java/org/bukkit/craftbukkit/profile/CraftPlayerProfile.java

@@ -161,7 +161,7 @@ public final class CraftPlayerProfile implements PlayerProfile {
 
     @Override
     public CompletableFuture<PlayerProfile> update() {
-        return CompletableFuture.supplyAsync(this::getUpdatedProfile, Util.backgroundExecutor());
+        return CompletableFuture.supplyAsync(this::getUpdatedProfile, Util.PROFILE_EXECUTOR); // Paper - don't submit BLOCKING PROFILE LOOKUPS to the world gen thread
     }
 
     private CraftPlayerProfile getUpdatedProfile() {