tests: fix DIFFICULTY error in state executor (#26465)

tests/state_test_util.go

@@ -249,16 +249,13 @@ func (t *StateTest) RunNoVerify(subtest StateSubtest, vmconfig vm.Config, snapsh
 	context.GetHash = vmTestBlockHash
 	context.BaseFee = baseFee
 	context.Random = nil
-	if config.IsLondon(new(big.Int)) {
-		if t.json.Env.Random != nil {
-			rnd := common.BigToHash(t.json.Env.Random)
-			context.Random = &rnd
-		}
+	if t.json.Env.Difficulty != nil {
+		context.Difficulty = new(big.Int).Set(t.json.Env.Difficulty)
+	}
+	if config.IsLondon(new(big.Int)) && t.json.Env.Random != nil {
+		rnd := common.BigToHash(t.json.Env.Random)
+		context.Random = &rnd
 		context.Difficulty = big.NewInt(0)
-	} else {
-		if t.json.Env.Difficulty != nil {
-			context.Difficulty = new(big.Int).Set(t.json.Env.Difficulty)
-		}
 	}
 	evm := vm.NewEVM(context, txContext, statedb, config, vmconfig)
 	// Execute the message.