test(ontology): name the contradicting rows instead of counting them

`diagnostics_do_not_contradict_the_readings_beside_them` reported "3 gpu
rows are present alongside it" and nothing else. That is enough to know a
contradiction exists and not enough to fix it, which matters here because
the assertion only fires on a machine with no GPU — not reachable from this
one.

It now lists the ids. The same information the test already had, printed
instead of discarded.

Surfaced by the previous commit: routing the no-GPU paths to `gpu.<none>`
made the diagnostic real, and the diagnostic promptly disagreed with three
rows nobody can currently name.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>