fix: PDB symbol link respect disable git features (#9490)

fix: PDB symbol link respect disable git features

Author: yufeih

src/Docfx.Dotnet/ManagedReference/Visitors/SymbolVisitorAdapter.cs

@@ -46,7 +46,7 @@ public override MetadataItem DefaultVisit(ISymbol symbol)
             DisplayNames = new SortedList<SyntaxLanguage, string>(),
             DisplayNamesWithType = new SortedList<SyntaxLanguage, string>(),
             DisplayQualifiedNames = new SortedList<SyntaxLanguage, string>(),
-            Source = VisitorHelper.GetSourceDetail(symbol, _compilation),
+            Source = _config.DisableGitFeatures ? null : VisitorHelper.GetSourceDetail(symbol, _compilation),
         };
         var assemblyName = symbol.ContainingAssembly?.Name;
         item.AssemblyNameList = string.IsNullOrEmpty(assemblyName) || assemblyName is "?" ? null : new List<string> { assemblyName };