remove test that's no longer useful
remove test that's no longer useful

This test is used to check if products are included in the fixture
only if they are modified after the last sync. Since we are
now caching the full function and busting the cache on any
product change the modified date check is no longer useful.

dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq