Add Slither reentrancy check in CI (#3047)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

contracts/token/ERC20/extensions/ERC20FlashMint.sol

@@ -56,6 +56,9 @@ abstract contract ERC20FlashMint is ERC20, IERC3156FlashLender {
      * @param data An arbitrary datafield that is passed to the receiver.
      * @return `true` is the flash loan was successful.
      */
+    // This function can reenter, but it doesn't pose a risk because it always preserves the property that the amount
+    // minted at the beginning is always recovered and burned at the end, or else the entire function will revert.
+    // slither-disable-next-line reentrancy-no-eth
     function flashLoan(
         IERC3156FlashBorrower receiver,
         address token,