distinguish between normal and test-only dependencies #68
Description
Test-only dependencies are those which are only referenced through some test. go mod why shows those with <package>.test along the path.
It would be useful to get the same information also in the depstat stats output by putting those test-only dependencies into a separate section. It doesn't change that test-only dependencies are dependencies of a module, but sometimes they can be considered less important.
Bonus points for doing a diff in https://github.com/kubernetes/test-infra/blob/de13c591665c718e2d3e169d9ad13c9aa7a52c5b/config/jobs/kubernetes/sig-arch/kubernetes-depstat.yaml#L34 such that the chunk with changes to normal and test-only dependencies contains the section name (similar to how it it shows the function in source code). Might be possible with Markdown formatting and a sufficiently intelligent diff (git diff instead of diff?).