nixos/nvidia: revert libXNVCtrl changes

This library does not actually need to match the Nvidia driver version,
so we do not need to make it available impurely.

This reverts the following commits.
9b3461e7ae
4e353b67f6

nixos/modules/hardware/video/nvidia.nix

@@ -285,7 +285,7 @@ in
             KERNEL=="nvidia_uvm", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-uvm-tools c $$(grep nvidia-uvm /proc/devices | cut -d \  -f 1) 1'"
           '';
           hardware.opengl = {
-            extraPackages = [ nvidia_x11.out ] ++ (lib.optional (builtins.hasAttr "libXNVCtrl" nvidia_x11.settings) nvidia_x11.settings.libXNVCtrl);
+            extraPackages = [ nvidia_x11.out ];
             extraPackages32 = [ nvidia_x11.lib32 ];
           };
           environment.systemPackages = [ nvidia_x11.bin ];