Disable progress ansi reporting on linux

Some terminals use this code to show notifications instead

DepotDownloader/Ansi.cs

@@ -31,6 +31,11 @@ static class Ansi
             return;
         }
 
+        if (OperatingSystem.IsLinux())
+        {
+            return;
+        }
+
         var (supportsAnsi, legacyConsole) = AnsiDetector.Detect(stdError: false, upgrade: true);
 
         useProgress = supportsAnsi && !legacyConsole;