BackgroundDocumentGenerator: Remove redundant calls

When iterating over `ProjectSnapshot.DocumentFilePaths`, it is redundant to call `ContainsDocument(...)` for those file paths on the same project. We already know it contains those file paths.

Author: DustinCampbell

src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/DynamicFiles/BackgroundDocumentGenerator.cs

@@ -201,10 +201,7 @@ private void ProjectManager_Changed(object sender, ProjectChangeEventArgs args)
 
                     foreach (var documentFilePath in newProject.DocumentFilePaths)
                     {
-                        if (newProject.ContainsDocument(documentFilePath))
-                        {
-                            Enqueue(new(newProject.Key, documentFilePath));
-                        }
+                        Enqueue(new(newProject.Key, documentFilePath));
                     }
 
                     break;
@@ -216,10 +213,7 @@ private void ProjectManager_Changed(object sender, ProjectChangeEventArgs args)
 
                     foreach (var documentFilePath in newProject.DocumentFilePaths)
                     {
-                        if (newProject.ContainsDocument(documentFilePath))
-                        {
-                            Enqueue(new(newProject.Key, documentFilePath));
-                        }
+                        Enqueue(new(newProject.Key, documentFilePath));
                     }
 
                     break;