refactor: replace doom-enlist with ensure-list

doom-enlist is now a deprecated alias for ensure-list, which is built
into Emacs 28.1+ and is its drop-in replacement. We've already
backported it for 27.x users in doom-lib (in 4bf4978).

Ref: 4bf49785fd

lisp/cli/packages.el

@@ -118,7 +118,7 @@ list remains lean."
        (dolist (,recipe-var ,recipes-var (nreverse built))
          (cl-block nil
            (straight--with-plist (append (list :recipe ,recipe-var) ,recipe-var)
-               ,(doom-enlist binds)
+               ,(ensure-list binds)
              ,@body))))))
 
 (defvar doom-packages--cli-updated-recipes nil)