Reintroduce libmagic to detect mime types
libmagic was removed in ab34e3f7 and 06703630 from the detection pipeline since zip files weren't detected correctly.
Since libmagic 3.33 (https://github.com/file/file/commit/ffaf85ec73ab939f4f6eadfe59bf2f639261d48c) this seems to be fixed.
@paobac Would it make sense to reintroduce libmagic?