Update `hardhat-ethers` to latest `ethers` with Pectra support

[kanej]

The latest version of ethers has been released, we need to update hardhat-ethers to use it:

• https://github.com/ethers-io/ethers.js/releases/tag/v6.14.0

The key addition is EIP-7702 support, which may require some supporting changes.

[kanej]

It has to be done in both v2 and v3.

[ChristopherDedominici]

The process to resolve this issue should be broken down into stages, as it requires some investigation to adapt the code to the changes in ethers:

1. update ethers to v6.14.0 and throw not implemented errors for the authorize and populateAuthorization methods. This ensures the code compiles while upgrading to the latest version of ethers. PR main, PR v-next

2. Investigate the changes in ethers and determine how to update these two new methods accordingly