modules: remove deprecated literalExample

modules/services/hardware/amdgpu-common.nix

@@ -7,7 +7,7 @@ with lib;
     cards = mkOption {
       type = types.listOf types.str;
       default = [ "card0" ];
-      example = literalExample ''[ "card0" ]'';
+      example = [ "card0" "card1" ];
       description = ''
         A list of cards to enable fan configuration for. The identifiers for
         each device can be found in /sys/class/drm/ as card0, card1, etc.

modules/services/hardware/amdgpu-fan.nix

@@ -33,14 +33,12 @@ in
         [ 75 89 ]
         [ 80 100 ]
       ];
-      example = literalExample ''
-        [
+      example = [
         [ 0 0 ]
         [ 40 30 ]
         [ 60 50 ]
         [ 80 100 ]
-        ]
-      '';
+      ];
       description = ''
         A list of temperature-fan speed pairs. The temperature is specified in
         degrees celcius, and speed is specified in %.

modules/services/x11/dunst.nix

@@ -17,17 +17,14 @@ in
       type = types.nullOr types.attrs;
       default = null;
       description = ''
-        Configuration set alternative to
-        <literalExpression>configFile</literalExpression>.
+        Configuration set alternative to <literal>configFile</literal>.
       '';
-      example = ''
-        {
+      example = {
         global = {
           monitor = 0;
           follow = "none";
         };
       };
-      '';
     };
 
     configFile = mkOption {