fix: remove redundant check in validPercentValue modifier

The validPercentValue modifier had a redundant check for `percent < 0` since
the parameter is of type uint256 which cannot be negative. Removed this check
to improve code clarity and gas efficiency.

contracts/payment/MCPayment.sol

@@ -92,7 +92,7 @@ contract MCPayment is Ownable2StepUpgradeable, EIP712Upgradeable {
      * @dev Valid percent value modifier
      */
     modifier validPercentValue(uint256 percent) {
-        if (percent < 0 || percent > 100) {
+        if (percent > 100) {
             revert InvalidOwnerPercentage("Invalid owner percentage");
         }
         _;