fix: invalid SStore gas computation

Author: delehef

arithmetization/src/main/java/net/consensys/linea/zktracer/opcode/gas/projector/SStore.java

@@ -30,9 +30,12 @@ public final class SStore implements GasProjection {
   public SStore(MessageFrame frame) {
     this.frame = frame;
     if (frame.stackSize() > 1) {
+      this.key = UInt256.fromBytes(frame.getStackItem(0));
       final Account account = frame.getWorldUpdater().getAccount(frame.getRecipientAddress());
+      if (account == null) {
+        return;
+      }
 
-      this.key = UInt256.fromBytes(frame.getStackItem(0));
       this.originalValue = account.getOriginalStorageValue(key);
       this.currentValue = account.getStorageValue(key);
       this.newValue = UInt256.fromBytes(frame.getStackItem(1));