ci: implement golang linter

[joelsmith-2019]

Would love some feedback on which linter rules we want and don't want. I threw them all in there essentially and wrote a note that they can be enabled/disabled on a per repo basis.

[joelsmith-2019]

Once the CodeQL repo get's merged, there will be a simple go module in the repo that this could try to lint. Right now its failing because it cannot find a go module.

[jtieri]

this looks pretty good! i went through the list of configured linters and made sure that all of the enabled ones make sense and provide something useful and these all seem good. i left a couple comments with some additional linters i would like to see added.

here is a full list of linters that golangci-lint provides, in case anyone else wants to pick through the list and see if there is something we ought to enable. maybe @mark-rushakoff has some insightful opinions here, if not i think this looks good to me and we can always iterate on this as necessary.

i'm unsure about making use of the make command in CI instead of using the actual GitHub action. i think we miss out on some performance gains if we don't use the action because it is optimized for CI and adds some things like smart caching. it also appears to provide annotations and logs that are easier to analyze when issues are found in CI so you don;t have to dig through the build logs. i know we discussed it means having to keep the versioning in check for both the Makefile and the GitHub action's config file but tbh i think the benefits the dedicated action provide outweigh the low burden of having to update versions in two places.

[joelsmith-2019]

All suggestions were implemented!

• Checks if go packages are installed in Makefile before installing again
• Adds all lint recommendations
• Now uses the golangci lint action instead of Makefile
• Adds make gofumpt to Makefile

[jtieri]

this looks great Joel, good job!!