Can't reference to ethers in hardhat tests

[OlivierKobialka]

PR: #14

Error

1) ================= PropertyNft Unit Tests =================
     "before each" hook for "Initializes the contract correctly":
   TypeError: Cannot read properties of undefined (reading 'JsonRpcProvider')

Code

beforeEach(async (): Promise<void> => {
    Nft = (await ethers.getContractFactory(
        "PropertyNft",
    )) as PropertyNft__factory;
    nft = await Nft.deploy(nftDeployer, nftName, nftSymbol);
});