misc: update solc to 0.8.28

[worm-emoji]

Description of changes

This pull request updates the version of solc used from 0.8.26 to 0.8.28. This is desired because Solidity 0.8.27 adds a variety of improvements to via IR builds, which v4 requires.

I understand if this won't be merged but figured I would attempt anyway so I don't have to use my fork of this repo :)

[hensha256]

Yeah sorry this wont be merged! Interested in how much it imprves gas though? Did you run forge test --isolate and push the gas snapshot changes?

[worm-emoji]

Just checked in the snapshots.