fix(astyanax): correct hostname typo from astynanax to astyanax

hosts/astyanax/default.nix

@@ -8,7 +8,7 @@
 
 let
   username = "h";
-  hostName = "astynanax";
+  hostName = "astyanax";
 in
 {
   system.stateVersion = "25.05";