Improve DPS test behavior with GHA problem matcher (CleverRaven#50125)

The problem matchers with GitHub actions are meant to make seeing errors
in tests easier, without having to navigate through the somewhat clumsy
interface to find the errors.
However, because the CHECK does not include the name of the item, this
is still required.
Move the CHECK to be on the line with the item name, so it is not
necessary to go through the clumsy GHA interface.

This does mean the test will not print failures and the expected value
to stdout. I think that being more compatible with the GHA problem
matchers is worth making this slightly more annoying to manually run.