Cats like to snuggle around their owners' necks while sleeping because they need a sense of security and a comfortable temperature. Also, kittens are often timid and need to seek security from their owners. Many cats will stay on their owners' laps, and some cats especially like their owners' necks.
Furthermore, if your cat often sleeps with its arms around your neck, it shows that it trusts you a lot. Therefore, the way you interact with it and the distance you maintain are probably comfortable for the cat. Please continue to shower it with love as always.
