base: restore unit dependencies are service.systemd_services

At runtime, systemd_services includes docker-* services too.
2 jobs for master in 3 minutes and 44 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #14883
ai3
run_base_test

00:03:41

passed #14884
ai3
run_buster_test

00:03:44