fnott: set icon theme (#1873)

Link: https://github.com/nix-community/stylix/pull/1873

Reviewed-by: NAHO <90870942+trueNAHO@users.noreply.github.com>
Reviewed-by: awwpotato <awwpotato@voidq.com>

modules/fnott/hm.nix

@@ -48,5 +48,12 @@ mkTarget {
           };
       }
     )
+    (
+      { polarity, icons }:
+      {
+        services.fnott.settings.main."icon-theme" =
+          if (polarity == "dark") then icons.dark else icons.light;
+      }
+    )
   ];
 }