[Phase-1] HIP-46: Abolish HIP-16 "Make admin roles eligible"

My motivation to make this HIP is that I don’t like HIP-16, it’s not just about the issues the HIP-16 has. I don’t want too much extra, confusing regulation.

and, there’s now this HIP-51 that suggests a different formalization and may be incompatible with HIP-16.