maintainers: add msgilligan (#421885)

maintainers/maintainer-list.nix

···
     githubId = 30654959;
     name = "Michele Sciabarra";
   };
+  msgilligan = {
+    email = "[e-mail]";
+    github = "msgilligan";
+    githubId = 61612;
+    name = "Sean Gilligan";
+    keys = [ { fingerprint = "3B66 ACFA D10F 02AA B1D5  2CB1 8DD0 D81D 7D1F C61A"; } ];
+  };
   msiedlarek = {
     email = "[e-mail]";
     github = "msiedlarek";

pkgs/by-name/sp/sparrow/package.nix

···
     license = licenses.asl20;
     maintainers = with maintainers; [
       emmanuelrosa
+      msgilligan
       _1000101
     ];
     platforms = [ "x86_64-linux" ];