chore: audit finding "Fee Address Is Using transfer"

packages/smart-contracts/src/contracts/BatchConversionPayments.sol

@@ -309,7 +309,10 @@ contract BatchConversionPayments is BatchNoConversionPayments {
     }
 
     require(address(this).balance >= batchFeeToPay, 'Not enough funds for batch conversion fees');
-    feeAddress.transfer(batchFeeToPay);
+    if (batchFeeToPay > 0) {
+      (bool feePaymentSuccess, ) = payable(feeAddress).call{value: batchFeeToPay}('');
+      require(feePaymentSuccess, 'Could not pay fees');
+    }
 
     // Batch contract transfers the remaining native tokens to the payer
     (bool sendBackSuccess, ) = payable(msg.sender).call{value: address(this).balance}('');

packages/smart-contracts/src/contracts/BatchNoConversionPayments.sol

@@ -200,7 +200,10 @@ contract BatchNoConversionPayments is Ownable {
     // Check that batch contract has enough funds to pay batch fee
     require(address(this).balance >= amount, 'Not enough funds for batch fee');
     // Batch pays batch fee
-    feeAddress.transfer(amount);
+    if (amount > 0) {
+      (bool feePaymentSuccess, ) = payable(feeAddress).call{value: amount}('');
+      require(feePaymentSuccess, 'Could not pay fees');
+    }
 
     // Batch contract transfers the remaining Native tokens to the payer
     if (transferBackRemainingNativeTokens && address(this).balance > 0) {