k3s: use nurl instead of nix-prefetch in update script

The changes introduced with #354367
lead currently to an evaluation error when prefetching vendored go
dependencies with `nix-prefetch`. Although this is probably a bug in
`nix-prefetch`, I prefer to use `nurl` instead as it does the same
thing, seems better maintained and doesn't block k3s updates even longer.

pkgs/applications/networking/cluster/k3s/update-script.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env nix-shell
-#!nix-shell -i bash -p curl gnugrep gnused jq yq-go nix-prefetch
+#!nix-shell -i bash -p curl gnugrep gnused jq nurl yq-go
 
 set -x -eu -o pipefail
 
@@ -141,7 +141,7 @@ cat >versions.nix <<EOF
 EOF
 
 set +e
-K3S_VENDOR_HASH=$(nix-prefetch -I nixpkgs=${NIXPKGS_ROOT} "{ sha256 }: (import ${NIXPKGS_ROOT}. {}).k3s_1_${MINOR_VERSION}.goModules.overrideAttrs (_: { vendorHash = sha256; })")
+K3S_VENDOR_HASH=$(nurl -e "(import ${NIXPKGS_ROOT}. {}).k3s_1_${MINOR_VERSION}.goModules")
 set -e
 
 if [ -n "${K3S_VENDOR_HASH:-}" ]; then