tests/__init__.py keeps a run offline, its scratch under tmp/ and its
installer cache its own, but only discover -s tests -t . imported it.
discover tests ran with RETROBIOS_OFFLINE unset, scratch on the /tmp
tmpfs and the user's real installer cache, the setting in which e2e
fixtures had written into the shared .cache/large. Every test module now
imports the package first, and a test fails on a module that does not.
test_verify_listing.py took its line with the previous commit.
AmberELEC's metapackage adds LIBRETRO_CORES_EXTRA (bsnes, Mesen, melonDS, geolith) only on RG552, RG353 and RG503, and deletes those cores from es_systems.cfg on every other device (packages/amberelec/package.mk:23-31, 45-58 at a21975bf). The new target scraper reads the Makefile's device images, that test and es_systems.cfg the way the platform scraper does: RG351P, RG351V and RG351MP list 125 cores, the other three 136. The installer reads the device from COREELEC_DEVICE in os-release (scripts/image:168).