Typescript error in knockout counter tests

[Hyodar]

Hello there!

It seems that the commit 73440a9 introduced a typescript error in some TestKnockoutCounter.ts unit tests, since the name hre is not known.

When writing tests in Typescript, the globally injected hre will not be recognized (confirmed by the docs), so one way to solve this would be to either import hre through import hre from "hardhat" or, since only the ethers module is being used, just import { ethers } from "hardhat" and changing usages accordingly would work. I've done this locally some days ago to be able to run the tests.

Let me know what you think. Cheers!