Fix #2995: doom-modeline save icon & ligature conflict

There is no good solution to this. I've decided the ligatures should
lose a character, instead of the modeline losing an icon.

modules/ui/pretty-code/+fira.el

@@ -119,6 +119,8 @@
 
 (defun +pretty-code-setup-fira-ligatures-h ()
   (set-fontset-font t '(#Xe100 . #Xe16f) +pretty-code-fira-code-font-name)
+  (when (featurep 'doom-modeline)
+    (set-fontset-font t #Xe161 nil))
   (setq-default prettify-symbols-alist
                 (append prettify-symbols-alist
                         (mapcar #'+pretty-code--correct-symbol-bounds

modules/ui/pretty-code/+iosevka.el

@@ -225,6 +225,8 @@
 
 (defun +pretty-code-setup-iosevka-ligatures-h ()
   (set-fontset-font t '(#Xe100 . #Xe1cc) +pretty-code-iosevka-font-name)
+  (when (featurep 'doom-modeline)
+    (set-fontset-font t #Xe161 nil))
   (setq-default prettify-symbols-alist
                 (append prettify-symbols-alist
                         +pretty-code-iosevka-font-ligatures)))