Update based on hexbytes.hex() changes

[trentmc]

Background / motivation

"If you're a Python dev doing web3 stuff, beware of the breaking change introduced in hexbytes v1.0. The hex() method no longer prepends '0x' to the hex string, so if you're doing keccak hashing be aware that it'll be all screwed up. The new method to_0x_hex() preserves the behavior.

Wasted the better part of a day debugging why my bundles were being rejected."

Ref: https://x.com/bowtieddevil/status/1809795540517023842?s=46

TODO

• Identify if this affects us
• Make necessary changes