Add Andrea's key to access staging

Signed-off-by: Benoit Donneaux <benoit@leastauthority.com>

morph/grid/testing/public-keys/users.nix

 let
   jcalderone = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIN4GenAY/YLGuf1WoMXyyVa3S9i4JLQ0AG+pt7nvcLlQ exarkun@baryon"];
   flo = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHx7wJQNqKn8jOC4AxySRL2UxidNp7uIK9ad3pMb1ifF flo@fs-la"];
+  andreas = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILkZzBoIPpoDSVis3HZId+lOI+3VTQfmz1uc4Yau8p/5 andreas@leastauthority.com"];
   ben = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIRJNhnYYllhiNhTNQg+IcfbAudxxWzk/VF45E9G9dMn benoit@leastauthority.com"];
 in
   {
-    "root" = jcalderone ++ flo ++ ben;
+    "root" = jcalderone ++ flo ++ andreas ++ ben;
     inherit jcalderone;
     inherit flo;
+    inherit andreas;
     inherit ben;
   }