Revert "[NixOS] Remove a possibly unnecessary addition to nvidia-container-toolkit-cdi-generator"

This reverts commit fca6d487f0.

nixos/k3s.nix

@@ -72,6 +72,14 @@ in {
       ];
     };
 
+    systemd.services = {
+      nvidia-container-toolkit-cdi-generator = {
+        # Even with `--library-search-path`, `nvidia-ctk` won't find the libs
+        # unless I bodge their path into the environment.
+        environment.LD_LIBRARY_PATH = "${config.hardware.nvidia.package}/lib";
+      };
+    };
+
     systemd.services.mount-railbird-bucket = {
       after = ["agenix.service"];
       wantedBy = [ "multi-user.target" ];