Ensure list is distinct.

src/EditorFeatures/Core.Wpf/NavigateTo/NavigateToItemProvider.Searcher.cs

@@ -100,6 +100,7 @@ private async Task SearchProjectsInPriorityOrder(IDocumentTrackingService docTra
                                                     .Select(d => _solution.GetDocument(d))
                                                     .Where(d => d != activeDocOpt)
                                                     .WhereNotNull()
+                                                    .Distinct()
                                                     .ToImmutableArray();
 
                 // First, if there's an active document, search that project first, prioritizing