Update contracts/contracts/sapphire/CrossChainPaymaster.sol

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: rube-de

contracts/contracts/sapphire/CrossChainPaymaster.sol

@@ -430,7 +430,8 @@ contract CrossChainPaymaster is
         uint256 validFeedCount = 0;
         uint8 commonRoseDec = 0; // Store decimals from first valid feed
 
-        for (uint256 i = 0; i < _roseUsdFeeds.length(); i++) {
+        uint256 roseUsdFeedCount = _roseUsdFeeds.length();
+        for (uint256 i = 0; i < roseUsdFeedCount; i++) {
             address feedAddr = _roseUsdFeeds.at(i);
             AggregatorV3Interface roseFeed = AggregatorV3Interface(feedAddr);