Due to the way GOPATH and vendoring works, copying Go tests out to a
random temp directory simply will not work. This is largely a holdover
to the days of when .pulumi/ directories would pollute the directory,
but is also done for languages like Node.js whose preparatory and build
steps also pollute the working directory (with bin/ and node_modules/
directories). Go does not have this problem, so we can safely skip.
c81a5152f0