Do not remove or reorder these setup steps.

active_storage/vips disables libvips’s unfuzzed loaders and savers. Requiring image_processing on its own is what raises the LoadError the engine reports when that gem is missing.

Do not require image_processing/vips when ruby-vips is unavailable: it requires ruby-vips a second time, and image_processing before 2.0.2 raises ImageProcessing::Error instead of LoadError, which aborts boot.