Three of the checks are temporarily disabled to limit the size of the
diff, and allow us to enable all the other checks in CI.
In a follow up we can fix the issues reported by the other checks one
at a time, and enable them.
Using golangci-lint has a number of advantages:
- adding new linters becomes much easier, its a couple lines of yaml config
instead of more bash scripting
- it enables whitelisting of issues using inline comments or regex
- when running multiple linters less work is done. The parsed source can be reused
by multiple linters
- linters are run in parallel to reduce CI runtime.