In the current context of contemporary languages I would consider system languages, having GC definitely defines one as abnormal, and Go is abnormal for a systems language. It was apparently much less uncommon to have GC system languages in the past (but I suspect those languages were well adapted to having fine grain memory control coupled with GC). Go is an interesting mix of low-level and close-to-the-metal with a few aspects which are not low-level (channels and GC).
Is Go an odd example then? What's a typical example? Better, out of the 10 or 20 most popular programming languages, which are "systems languages" and which are not? I genuinely don't know how to tell, other than maybe "no GC". As far as I can tell the term mainly just means "language I like".