fix(base): gnus-group-news-low-empty: face inheritance cycle

By default, `gnus-group-news-low` inherits from
`gnus-group-news-low-empty`. doom-themes tries to reverse this by
inheriting `gnus-group-news-low-empty` from `gnu-group-news-low`, but
before latter can be redefined, Emacs 31+ throws an cyclical face
inheritance error, so swap the order that these faces are changed.

Fix: #875

Author: hlissner

doom-themes-base.el

@@ -674,8 +674,8 @@
     (gnus-group-news-6-empty     :inherit 'gnus-group-news-1-empty)
     (gnus-group-mail-low         :inherit 'gnus-group-mail-1 :weight 'normal)
     (gnus-group-mail-low-empty   :inherit 'gnus-group-mail-1-empty)
-    (gnus-group-news-low         :inherit 'gnus-group-mail-1 :foreground base5)
     (gnus-group-news-low-empty   :inherit 'gnus-group-news-low :weight 'normal)
+    (gnus-group-news-low         :inherit 'gnus-group-mail-1 :foreground base5)
     (gnus-header-content         :inherit 'message-header-other)
     (gnus-header-from            :inherit 'message-header-other)
     (gnus-header-name            :inherit 'message-header-name)