feat(nixos): cut over Gitea to Pikachu

configs/nixos/modules/network/ssh.nix

@@ -33,10 +33,9 @@ let
   });
 
   extraTargets = {
-    # TODO: Pin Gitea's host key after migrating it from Proxmox.
+    # TODO: Pin Gitea's host key after deploying its Pikachu guest.
     gitea = {
       hostName = "git.alexion.dev";
-      port = 2022;
       user = "gitea";
       aliases = [
         "gitea"