Fix erroneous logger disposal

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CSharp/Extractor/Analyser.cs

@@ -312,8 +312,6 @@ public virtual void Dispose()
             else
                 Logger.Log(Severity.Info, "EXTRACTION SUCCEEDED in {0}", stopWatch.Elapsed);
 
-            Logger.Dispose();
-
             compilationTrapFile?.Dispose();
         }