nuget-to-nix: use xmlstarlet instead of xq (yq)

xq has such a long startup time that this significantly improves
performance.

pkgs/build-support/dotnet/nuget-to-nix/default.nix

@@ -5,7 +5,7 @@
 , nix
 , coreutils
 , jq
-, yq
+, xmlstarlet
 , curl
 , gnugrep
 , gawk
@@ -21,7 +21,7 @@ runCommandLocal "nuget-to-nix" {
       nix
       coreutils
       jq
-      yq
+      xmlstarlet
       curl
       gnugrep
       gawk

pkgs/build-support/dotnet/nuget-to-nix/nuget-to-nix.sh

@@ -51,7 +51,7 @@ for package in *; do
   [[ -d "$package" ]] || continue
   cd "$package"
   for version in *; do
-    id=$(xq -r .package.metadata.id "$version"/*.nuspec)
+    id=$(xmlstarlet sel -t -v /_:package/_:metadata/_:id "$version"/*.nuspec)
 
     if grep -qxF "$id.$version.nupkg" "$excluded_list"; then
       continue