ci: remove inconvenient convenience symlinks (#4933)
ci: remove inconvenient convenience symlinks (#4933)

Bazel creates "convenience" links in %workspace% pointing to the
location of several interesting directories. These links are wrong when
created inside a Docker container, which is the case for most of our
builds, better to not generate the links in the first place.
googleapis/google-cloud-cpp,googleapis/google-cloud-cpp,googleapis/google-cloud-cpp,googleapis/google-cloud-cpp