[Example] Changed nxcShellFull to nxcShell as the naming convention changed.

Note to devs: this change was not made in the other examples,
leading to the ubiquitous use of nxcShell (and absence of
nxcShellLite) in examples. This is a deliberate choice to avoid
any potential bug introduced by removing tmux support or any
other feature. Feel free to downgrade nxcShell to nxcShellLite
in some examples if possible.

Author: Pierre-François

examples/nixos-cluster/flake.nix

@@ -22,6 +22,6 @@
       defaultPackage.${system} =
         self.packages.${system}."composition::vm";
 
-      devShell.${system} = nxc.devShells.${system}.nxcShellFull;
+      devShell.${system} = nxc.devShells.${system}.nxcShell;
     };
 }