Fix goreleaser for Go 1.16

[jdknives]

Describe the bug
Golang 1.16 and the latest version of goreleaser (goreleaser version 0.157.0) fail when creating a release for Skywire.

There may be two issues here

1. https://goreleaser.com/deprecations/#builds-for-darwinarm64
   There seems to be this new build target that we do not need. We should add the ignore config as suggested in this resource.

2. With Go 1.16, there is a vendoring issue it seems. Building arm64 breaks with some error stating something to the effect that /pkg/util/stdio/arm_dup.go is undefined.