ci(gitlab-ci): use templates from a common repository

4 jobs for branch/default in 2 minutes and 15 seconds (queued for 20 seconds)
Status Name Job ID Coverage
  Lint
passed black #364205

00:00:28

passed check-manifest #364206

00:00:22

passed flake8 #364204

00:00:34

 
  Tests
passed py3 #364207

00:01:41