Fix typo (#3241)

Fix camelcase of 'lastvalue' to 'lastValue'

contracts/utils/structs/EnumerableSet.sol

@@ -83,12 +83,12 @@ library EnumerableSet {
             uint256 lastIndex = set._values.length - 1;
 
             if (lastIndex != toDeleteIndex) {
-                bytes32 lastvalue = set._values[lastIndex];
+                bytes32 lastValue = set._values[lastIndex];
 
                 // Move the last value to the index where the value to delete is
-                set._values[toDeleteIndex] = lastvalue;
+                set._values[toDeleteIndex] = lastValue;
                 // Update the index for the moved value
-                set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
+                set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
             }
 
             // Delete the slot where the moved value was stored