fix: remove flashloan receiver

test/blue_tests.tree

@@ -209,7 +209,7 @@
                 │   └── it should call sender's onBlueLiquidate callback
                 └── it should transfer repaid of borrowable asset from the sender the Blue
 .
-└── flashLoan(IFlashBorrower receiver, address token, uint256 amount, bytes calldata data) external
+└── flashLoan(address token, uint256 amount, bytes calldata data) external
     ├── it should transfer amount of token from Blue to the sender
     ├── it should call sender's onBlueFlashLoan callback
     ├── it should emit FlashLoan(msg.sender, token, amount)