refactor: capitalize immutable variables

.solhint.json

@@ -7,7 +7,6 @@
     "contract-name-camelcase": "off",
     "const-name-snakecase": "off",
     "custom-errors": "off",
-    "immutable-vars-naming": "off",
     "func-name-mixedcase": "off",
     "func-visibility": ["error", { "ignoreConstructors": true }],
     "max-line-length": ["error", 123],

src/abstracts/NoDelegateCall.sol

@@ -7,11 +7,11 @@ import { Errors } from "../libraries/Errors.sol";
 /// @notice This contract implements logic to prevent delegate calls.
 abstract contract NoDelegateCall {
     /// @dev The address of the original contract that was deployed.
-    address private immutable _original;
+    address private immutable ORIGINAL;
 
     /// @dev Sets the original contract address.
     constructor() {
-        _original = address(this);
+        ORIGINAL = address(this);
     }
 
     /// @notice Prevents delegate calls.
@@ -23,11 +23,11 @@ abstract contract NoDelegateCall {
     /// @dev This function checks whether the current call is a delegate call, and reverts if it is.
     ///
     /// - A private function is used instead of inlining this logic in a modifier because Solidity copies modifiers into
-    /// every function that uses them. The `_original` address would get copied in every place the modifier is used,
+    /// every function that uses them. The `ORIGINAL` address would get copied in every place the modifier is used,
     /// which would increase the contract size. By using a function instead, we can avoid this duplication of code
     /// and reduce the overall size of the contract.
     function _preventDelegateCall() private view {
-        if (address(this) != _original) {
+        if (address(this) != ORIGINAL) {
             revert Errors.DelegateCall();
         }
     }

test/fork/Fork.t.sol

@@ -12,8 +12,8 @@ abstract contract Fork_Test is Base_Test {
                                      CONSTANTS
     //////////////////////////////////////////////////////////////////////////*/
 
-    IERC20 internal immutable asset;
-    address internal immutable holder;
+    IERC20 internal asset;
+    address internal holder;
 
     /*//////////////////////////////////////////////////////////////////////////
                                      VARIABLES