Update gohashtree dependency

[come-maiz]

We are packaging mev-boost, geth and other ethereum software for debian. We are reviewing all the dependency chain, and we got blocked in the gohashtree dependency because of prysmaticlabs/gohashtree#21
We fixed it and to move up on the next layer of dependencies we will need an update here to the latest version of gohashtree and a new release.

We are not in a rush, this is all slow patient work.

I'll send a pull request for this update.

^_^