Add test to catch completely malfunctioning Product List

[sterlinghirsh]

We deployed a change with an accidentally updated pnpm lock. This ended up breaking the collection page in some cases. Unfortunately, this meant we served many many error pages (28k according to sentry). It's unclear how tests didn't catch this problem. Perhaps the patch to react-instantsearch-hooks wasn't working, which breaks the site in prod but doesn't break tests.