drop .github/workflows/lints.yml

In [1] we configured repo-templates to push the go and shellcheck
workflows to the COSA repo. Right now the existing golangci-lint
workflow here is failing because of golang versions. Let's just drop
the existing lints here prematurely knowing that we are going to move
to the new repo-templates provided linters in [2].

[1] coreos/repo-templates#359
[2] #4468

Author: dustymabe