treewide: use mkWarnings where possible

modules/lazyload.nix

@@ -45,14 +45,16 @@ in
         ) (builtins.attrNames config.plugins);
         count = builtins.length pluginsWithLazyLoad;
       in
-      lib.optionals (count > 0 && !config.plugins.lz-n.enable) [
-        ''
+      lib.nixvim.mkWarnings "lazy loading" {
+        when = count > 0 && !config.plugins.lz-n.enable;
+
+        message = ''
           You have enabled lazy loading support for the following plugins but have not enabled a lazy loading provider.
             ${lib.concatImapStringsSep "\n" (i: x: "${toString i}. plugins.${x}") pluginsWithLazyLoad}
 
           Currently supported lazy providers:
             - lz-n
-        ''
-      ];
+        '';
+      };
   };
 }