Remove TODO for ExplosionMixin onExplosionHit

Didn't need to be ported to Paper, was only broken here.

src/main/java/ca/spottedleaf/moonrise/mixin/collisions/ExplosionMixin.java

@@ -509,7 +509,7 @@ public void explode() {
                 }
             }
 
-            entity.onExplosionHit(this.source); // TODO port to paper
+            entity.onExplosionHit(this.source);
         }
 
         this.blockCache = null;