feat(git): enable recursive submodule update by default

Added `submodule.recurse = true` to the git configuration in NixOS. This change ensures that submodules are automatically updated recursively.

modules/nixos/tools/git/default.nix

@@ -55,6 +55,7 @@ in
           merge.conflictStyle = "diff3";
           diff.colorMoved = "default";
           http.sslCAinfo = "/etc/ssl/certs/ca-certificates.crt";
+          submodule.recurse = true;
         };
       };
     };