refactor: deprecate appendq!, prependq!, & delq! macros

In the interest of slimming down Doom's core (as we near v3), I've
deprecated these macros. They doesn't really need to exist. Sure, the
alternatives aren't as ergonomic or elegant, but they're good enough
that we don't need these trivial wrappers. Their local uses have been
refactored out as well.

modules/ui/ligatures/autoload/ligatures.el

@@ -35,7 +35,7 @@ Note that this will keep all ligatures in `+ligatures-prog-mode-list' active, as
   (declare (indent defun))
   (if (null (car-safe plist))
       (dolist (mode (ensure-list modes))
-        (delq! mode +ligatures-extra-alist 'assq))
+        (setf (alist-get mode +ligatures-extra-alist nil t) nil))
     (let ((results))
       (while plist
         (let ((key (pop plist)))

modules/ui/modeline/+light.el

@@ -474,7 +474,7 @@ lines are selected, or the NxM dimensions of a block selection.")
 (defun +modeline-add-selection-segment-h ()
   (add-to-list '+modeline-format-left '+modeline-selection-info 'append))
 (defun +modeline-remove-selection-segment-h ()
-  (delq! '+modeline-selection-info +modeline-format-left))
+  (cl-callf2 delq '+modeline-selection-info +modeline-format-left))
 
 (if (featurep 'evil)
     (progn