Remove support for old clone/fetch methods
Description
GitLab Runner now requires Refspec information in the job response to clone the project which is sent from a GitLab instance that is running version %11.9+
Proposal
Remove the old code which used to clone and fetch the repository
Links to related issues and merge requests / references
Main deprecation issue #3473 (closed) MR introducing new clone/fetch method !1203 (merged)