Fix loop sound persisting after the payload carrier is removed. (#8034)

* Properly remove units and blocks in the case that the carrier dies

* added = false

---------

Co-authored-by: Anuken <arnukren@gmail.com>

core/src/mindustry/world/blocks/payloads/BuildPayload.java

@@ -82,6 +82,11 @@ public class BuildPayload implements Payload{
         return build.block.size * tilesize;
     }
 
+    @Override
+    public void remove(){
+        build.stopSound();
+    }
+
     @Override
     public void write(Writes write){
         write.b(payloadBlock);

core/src/mindustry/world/blocks/payloads/Payload.java

@@ -75,6 +75,8 @@ public interface Payload extends Position{
         return y();
     }
 
+    default void remove(){}
+
     static void write(@Nullable Payload payload, Writes write){
         if(payload == null){
             write.bool(false);