Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Only run verify-staging-godeps if staging/godeps are touched

**What this PR does / why we need it**:
I had a lightbulb moment. On presubmit, we only verify godeps if one of the following is changed:
- The godep scripts
- The Godeps/ dir
- The vendor/ dir

The same should apply to verifying the staging godeps, adding in the staging dir itself. The logic being, if we don't touch Godeps/vendor, we don't touch the script that generates stuff, and we don't make changes to the staging dir itself (like adding/removing imports), then we don't need to verify godeps.

Note that post-submit CI jobs will still check these, as I'm copying the same logic that's in verify-godeps

This seems too easy, so *please* point out if I'm missing something.

**Release note**:
```release-note
NONE
```