I am getting this problem and I have read someone else having the same issue saying that they fixed the issue by downgrading their ethers file. I deleted the node_modules folder and reran npm install. This reinstalled everything but did not fix the problem.
npx hardhat run --network sepolia scripts/deployFlashLoan.js Error: Package subpath './lib/utils' is not defined by "exports" in /home/cryptosoaring/node_modules/ethers/package.json