Please remove the varnamelen linter

[jech]

In the last months, Pion has acquired large numbers of new linters that dramatically increase the amount of work required to submit a PR. What should be a three-minute job now requires multiple back-and-forths between the command line and the github interface while we make random wording changes until the linters are satisfied. Sacrificing an immaculate lamb over the keyboard helps, but doesn't completely solve the issue.

I have already mentioned the nakedret (pion/webrtc#3331) and nlreturn (pion/webrtc#3334) linters, each of which caused me additional round-trips while I was making minor changes to Pion.

The first commit in #862 consistently uses the name a to refer to the agent. Unfortunately the varnamelen linter is opposed to consistency, and requires using a different name if a function is longer than some arbitrary threshold.

Please remove the varnamelen linter.

[JoTurk]

@jech we had this linter for more then a year and people find it more helpful. we have some exceptions for common types, we can add a for agents, I think. and common local types for some of our libraries when it makes sense.

https://github.com/pion/.goassets/blob/master/ci/.golangci.yml#L122-L126

[JoTurk]

please reopen this in .goassets if you're still interested we don't manage lint rules per repo.