DRY actions config with matrix syntax
DRY actions config with matrix syntax

This uses the matrix syntax for all rspec calls. It is easier to
maintain than the previous list of GH Actions workflows.

The execution of the rspec rake task is still in its own job because it
doesn't fit in the same pattern. The JS tests are also executed in that
job.

lin-d-hop/openfoodnetwork,openfoodfoundation/openfoodnetwork,openfoodfoundation/openfoodnetwork,Matt-Yorkley/openfoodnetwork,lin-d-hop/openfoodnetwork,lin-d-hop/openfoodnetwork,Matt-Yorkley/openfoodnetwork,mkllnk/openfoodnetwork,openfoodfoundation/openfoodnetwork,mkllnk/openfoodnetwork,Matt-Yorkley/openfoodnetwork,Matt-Yorkley/openfoodnetwork,lin-d-hop/openfoodnetwork,mkllnk/openfoodnetwork,mkllnk/openfoodnetwork,openfoodfoundation/openfoodnetwork