common-gpu-nvidia: remove redundant config

[matdibu]

nixos-hardware/common/gpu/nvidia/default.nix

Lines 6 to 7 in fb08bde

	# TODO: this will be a default after https://github.com/NixOS/nixpkgs/pull/326369
	hardware.nvidia.modesetting.enable = lib.mkDefault true;

this has been merged for a while[1], can/should we delete hardware.nvidia.modesetting.enable ?

1. https://github.com/NixOS/nixpkgs/pull/326369/files

[Mic92]

This is still needed for 24.06. It can be removed after 24.11 is out.

[matdibu]

right, I forgot not everybody is using nixos-unstable