Fix list capacity calculation in GetGraphItemAsync that is leading to list resizing based allocations (#7026)

Author: nareshjo

src/NuGet.Core/NuGet.Commands/RestoreCommand/DependencyGraphResolver.DependencyGraphItem.cs

@@ -97,7 +97,7 @@ public async Task<GraphItem<RemoteResolveResult>> GetGraphItemAsync(
                 }
 
                 // Create a new list that is big enough for the existing items plus any runtime dependencies
-                List<LibraryDependency> dependencies = new(capacity: RuntimeDependencies?.Count ?? 0 + item.Data.Dependencies.Count);
+                List<LibraryDependency> dependencies = new(capacity: (RuntimeDependencies?.Count ?? 0) + item.Data.Dependencies.Count);
 
                 // Loop through the defined dependencies, leaving out any pruned packages or runtime packages that replace them
                 for (int i = 0; i < item.Data.Dependencies.Count; i++)