Merge branch 'make-flo-root-on-prod-too' into 'develop'

Add flo to prod: ssh key + root access

See merge request !292

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

 let
   jcalderone = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGN4VQm3BIQKEFTw6aPrEwNuShf640N+Py2LOKznFCRT exarkun@bottom"];
+  flo = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAII6EUU/KNDr7y3m5OVWBZAuPiMJ4us3YOBEhxpG29yPN flo@la"];
 in {
-  "root" = jcalderone;
+  "root" = jcalderone ++ flo;
   "jcalderone" = jcalderone;
+  "flo" = flo;
 }