CI: add --no-cache option to docker build, to clear out stale cache

4 jobs for master in 2 minutes and 23 seconds (queued for 1 second)
Status Name Job ID Coverage
  Dist
passed gwinc/base #1139147

00:01:09

 
  Test
passed generate_budgets #1139148

00:00:50

 
  Deploy
passed pages #1139149

00:00:23

passed pages:deploy

00:00:01