Skip test on CoreClr

src/Compilers/Server/VBCSCompilerTests/TouchedFileLoggingTests.cs

@@ -29,7 +29,7 @@ public static void Main(string[] args)
     }
 }";
 
-        [ConditionalFact(typeof(WindowsOnly))]
+        [ConditionalFact(typeof(DesktopOnly))]
         public void TrivialMetadataCaching()
         {
             List<String> filelist = new List<string>();