global: Support Go-1.17-style build tags
With Go 1.17, new syntax was introduced for build tags which has the
intent to be much easier to use compared to the previous +build
ones.
To ease the migration, Go 1.17 supports both old-style and new-style
build tags, where the recommended migration path is to have both as long
as projects support older Go versions which don't yet know about the new
syntax.
Migrate our codebase to use both both styles. While we don't yet support Go 1.17 officially, it doesn't hurt to be prepared, and furthermore it fixes linting issues I have been observing on my machine.