Fix a minor mistake calling progress.update (should be `completed`).

See !81 (comment 147251)
3 jobs for topic/default/fig-progress-update in 9 minutes and 44 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #133172
step_pythran_cython

00:09:44

passed #133171
step_pythran_then_cython

00:07:43

passed #133170
step_without_pythran

00:04:55