fix: remove assert to check cache format

[mattsse]

Motivation

removes an assert! that would cause a panic if the project was previously built with hardhat.

it is not required that the format ids match and is currently used to provide a way to distinguish whether the file was previously built with hardhat.

I'm not sure what the most straight forward approach to remove possible friction between ethers-solc/foundry builds and hardhat would be

possible solutions:

• always check for matching ethers format id, treat cache as empty if it was written by hardhat
• use a different cache file than hardhat
• keep it like it is and make MinimalCombinedArtifactsHardhatFallback artifact output the default which supports reading hardhat style artifacts

Solution

PR Checklist

• Added Tests
• Added Documentation
• Updated the changelog