binarycaching: Set BinaryProviders::nuget_repo & remove unused field (

#1360)

The former wasn't getting set anywhere even though `BinaryCache::push_success()` uses it.

Also remove unused `BinaryConfigParserState::nuget_repo_info` field.

include/vcpkg/binarycaching.h

@@ -157,7 +157,6 @@ namespace vcpkg
         // These are filled in after construction by reading from args and environment
         std::string nuget_prefix;
         bool use_nuget_cache = false;
-        NuGetRepoInfo nuget_repo_info;
 
         void clear();
     };

src/vcpkg/binarycaching.cpp

@@ -1880,8 +1880,11 @@ namespace vcpkg
 
             s.nuget_prefix = args.nuget_id_prefix.value_or("");
             if (!s.nuget_prefix.empty()) s.nuget_prefix.push_back('_');
+            ret.nuget_prefix = s.nuget_prefix;
+
             s.use_nuget_cache = args.use_nuget_cache.value_or(false);
-            s.nuget_repo_info = get_nuget_repo_info_from_env(args);
+
+            ret.nuget_repo = get_nuget_repo_info_from_env(args);
 
             auto& fs = paths.get_filesystem();
             auto& tools = paths.get_tool_cache();