test: Fix configuring the Cilium agent
test: Fix configuring the Cilium agent

The helpers file was assuming that the test path is mounted into the
target VM at the location "/vagrant", but this is not the case for the
developer VM so if you attempt to run the ginkgo runtime CI against the
dev VM you'll hit this error:

  Expected
      <*errors.errorString | 0xc0004b0900>: {
          s: "cp: cannot stat '/vagrant/cilium': No such file or directory\n",
      }
  to be nil

Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@cilium.io>

cilium/cilium,cilium-team/cilium,cilium/cilium,tgraf/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,tgraf/cilium,michi-covalent/cilium,michi-covalent/cilium,tgraf/cilium,michi-covalent/cilium,tgraf/cilium,cilium/cilium,cilium-team/cilium,tklauser/cilium,michi-covalent/cilium