chore:

- Extracted variance seed derivation to deriveVarianceSeed

Ref.: https://github.com/VolmitSoftware/Iris/issues/1251

core/src/main/java/art/arcane/iris/generation/decoration/IrisDecorator.java

@@ -158,10 +158,14 @@ public class IrisDecorator {
 
         return varianceGenerator.aquire(() ->
                 variance.create(
-                                rng.nextParallelRNG(getBlockData(data).size()), data)
+                                deriveVarianceSeed(rng, data), data)
                         .scale(1D / variance.getZoom()));
     }
 
+    RNG deriveVarianceSeed(RNG rng, IrisData data) {
+        return rng.nextParallelRNG(getBlockData(data).size());
+    }
+
     public KList<IrisBlockData> add(String b) {
         palette.add(new IrisBlockData(b));
         return palette;