don't assume items are queried in any specific order in interactive delete test
don't assume items are queried in any specific order in interactive delete test

The previous test worked (on my machine, and on Github CI and AppVeyor),
but it is not obvious whether the order is really guaranteed (given that
the full beets database stack and sqlite are involved). Thus, to prevent
this from exploding at some point, only verify the number of deletions
for now.

beetbox/beets,beetbox/beets,beetbox/beets,sampsyo/beets,shamangeorge/beets,ibmibmibm/beets,ibmibmibm/beets,sampsyo/beets,ibmibmibm/beets,jackwilsdon/beets,jackwilsdon/beets,shamangeorge/beets,sampsyo/beets,beetbox/beets,ibmibmibm/beets,shamangeorge/beets,sampsyo/beets,jackwilsdon/beets,jackwilsdon/beets,shamangeorge/beets