maintainers: arcadio, update email (#421861)

maintainers/maintainer-list.nix

···
     name = "Arbel Arad";
   };
   arcadio = {
-    email = "[e-mail]";
+    email = "[e-mail]";
     github = "arcadio";
     githubId = 56009;
     name = "Arcadio Rubio García";