Bump go versions in .github/workflows/go.yml (#1237)
Bump go versions in .github/workflows/go.yml (#1237)

* Bump go versions in .github/workflows/go.yml

These are very out of date and it's causing persistent failures in the
fuzz CI step.

* Remove GOPATH=$GOROOT assignment

go1.16 shows a warning:
  "warning: GOPATH set to GOROOT (/opt/hostedtoolcache/go/1.16.0/x64) has no effect"
miekg/dns