golangci: remove several linters
Created by: keegancsmith
Went through the list of linters and removed the following:
- depguard - Go linter that checks if package imports are in a list of acceptable packages - We don't have it configured.
- funlen - Tool for detection of long functions - noisy
- goconst - Finds repeated strings that could be replaced by a constant - I'd rather write ".git" than kDOTGIT. We aren't C++/objc.
- gocritic - The most opinionated Go source code linter - the description made me remove it.
- gofmt - goimports does everything gofmt does.
- scopelint - Scopelint checks for unpinned variables in go programs - we already have warnings about shadowing in more robust tools.