Add golang-tip to CI

[AlekSi]

Use https://github.com/AlekSi/golang-tip instead of recompiling tip every time.

[kevholmes]

Hi there @AlekSi - I'll try and take a look at this in the next day or two.

[AlekSi]

@kevholmes I case you are here for Hacktoberfest, I just opted-in golang-tip repo. So you could start with golang-tip's README update: adding instructions for GitHub Actions would be helpful for everyone.