Only mark decorations dirty if a removal actually occurs (#11413)

* Only mark decorations dirty if a removal actually occurs

Vanilla calls this method blindly inside of a loop which erroniously marks
map data files as being dirty even if nothing has actually changed.

* Merge into existing patch

---------

Co-authored-by: Bjarne Koll <lynxplay101@gmail.com>

patches/server/0987-Improve-Maps-in-item-frames-performance-and-bug-fixe.patch

@@ -44,7 +44,7 @@ index d0b51d96d6795b5fa03bc195b90324680545b752..09bcbc0ae36e4e69fee87a7e0c49acf4
              return entityitem;
          }
 diff --git a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
-index a43544704109f21bab230dd9bf0401e28f878582..17f33c83c6033564d6bf4fbd388b0b847c68adb3 100644
+index a43544704109f21bab230dd9bf0401e28f878582..6794466051dd4b725d579b2136c37844995a648e 100644
 --- a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
 +++ b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
 @@ -79,6 +79,7 @@ public class MapItemSavedData extends SavedData {
@@ -71,6 +71,15 @@ index a43544704109f21bab230dd9bf0401e28f878582..17f33c83c6033564d6bf4fbd388b0b84
  
          RegistryOps<Tag> registryops = registryLookup.createSerializationContext(NbtOps.INSTANCE);
          List<MapBanner> list = (List) MapBanner.LIST_CODEC.parse(registryops, nbt.get("banners")).resultOrPartial((s) -> {
+@@ -348,7 +351,7 @@ public class MapItemSavedData extends SavedData {
+             --this.trackedDecorationCount;
+         }
+ 
+-        this.setDecorationsDirty();
++        if (mapicon != null) this.setDecorationsDirty(); // Paper - only mark dirty if a change occurs
+     }
+ 
+     public static void addTargetDecoration(ItemStack stack, BlockPos pos, String id, Holder<MapDecorationType> decorationType) {
 @@ -588,6 +591,21 @@ public class MapItemSavedData extends SavedData {
  
      public class HoldingPlayer {