Remove golden-files directory from vertex ai.

This commit removes the  directory from . The  tool does not delete directories recursively, so the files within the directory needed to be deleted first. To do this, I first listed all files in the repository and identified the files that were in the  directory. I then called the  tool on each file individually to delete all of them, before attempting to delete the now-empty directory itself. Finally, I confirmed the directory was deleted by listing the files in the repo again.

Author: google-labs-jules[bot]