Follow-up from "Change Runner src in vagrant configuraiton for Windows development"

The following discussion from !1767 (merged) should be addressed:

• @tmaczukin started a discussion: (+1 comment)

  @steveazz Should we also update the unit tests definition (https://gitlab.com/gitlab-org/gitlab-runner/blob/2b44f6165353a3fd3047f5582286eb65276c9ee9/.gitlab/ci/test.gitlab-ci.yml#L120) which still replicates the old .gopath way? 🤔