Remove Reliance on OSX Cross Dependency for Goreleaser

[aaronbuchwald]

Context and scope
The current goreleaser job installs an OSX Cross compiler dependency in order to support the blst library imported by AvalancheGo. This is a bit messy and probably not the most reliable, so we should prioritize removing it from the goreleaser job in favor of a different solution.

One approach may be to run goreleaser on a Mac runner to support the mac builds instead of requiring the OSX Cross Dependency.

Discussion and alternatives
We discussed improving the way it was installed here: #300 but decided it would be better to find a different approach.

Useful information on goreleaser with CGO here: https://goreleaser.com/cookbooks/cgo-and-crosscompiling/