Update EveryBeam ci/cd

The EveryBeam pipeline pushes and pulls to an image registry (docker.io). This however is not needed, since we can re-use images from cache, thereby simplifying the EveryBeam CI (see also DP3 ci yml file as an example).

Fixing this story should also involve adding "line coverage" (see https://github.com/lofar-astron/DP3/pull/270)

For those with jira access, see https://jira.skatelescope.org/secure/RapidBoard.jspa?rapidView=184&view=planning&selectedIssue=AST-110