Omit unnecessary JS boilerplate for GObject properties
Quoting the main commit:
js: Use gjs-defined GObject accessors where possible
Nowadays gjs allows to omit get/set accessors for read-write properties,
and will define reasonable defaults in that case. In many cases we don't
need anything more than the default handling, and in almost all remaining
cases, we can handle the "special" bits in a notify handler.