Add filecoin-shipyard/jiffy to Golang unified CI

[masih]

Necessary permissions have already been granted to @web3-bot.

See: https://github.com/filecoin-shipyard/jiffy

[galargh]

Hey! Thanks for the PR. We're finishing up a transition to the new version of Unified CI (https://github.com/pl-strflt/uci). In that one, all you have to do to sign up is to grant @web3-bot access to the repo - no further steps necessary. Which means that you're all done :)

I'll be putting out a broader announcement about this and other cool changes later today or on Monday. I just have to put one last thing in place, which is for the Unified CI to start automatically noticing when a new repo is introduced (so far I've been doing it manually to make sure it works properly).