refactor(cli): remove :stub, :obsolete, :deprecated, :since

I've removed these CLI properties because they were either
unused (:deprecated and :since) or poorly implemented (:stub and
:obsolete). And I'd rather have fewer magical properties, and instead
delegate these roles to the defobsolete! and (new) defstub!  macros.
Also, in the future, the help API will ascertain :since dynamically, so
it won't be very useful.

In summary:
- Use defstub! instead of :stub
- Use defobsolete! instead of :obsolete or :deprecated
- This removes the doom-cli-deprecated-error type (it's not really an
  error to begin with).
- Removes :stub, :obsolete, :deprecated, and :since

core/cli/sync.el

@@ -67,7 +67,7 @@ OPTIONS:
     (remove-hook 'kill-emacs-hook #'doom-sync--abort-warning-h)))
 
 ;; DEPRECATED Remove when v3.0 is released
-(defobsolete! ((refresh re)) "doom sync" "v3.0.0")
+(defobsolete! ((refresh re)) (sync) "v3.0.0")
 
 
 ;;