Add logging for worker bundle is detected (#4281)

@soninaren, merging this in so you can pick it up for the release

Author: maiqbal11

src/WebJobs.Script.WebHost/Management/InstanceManager.cs

@@ -169,6 +169,12 @@ private async Task ApplyContext(HostAssignmentContext assignmentContext)
                     ZipFile.ExtractToDirectory(filePath, options.ScriptPath, overwriteFiles: true);
                     _logger.LogInformation($"Zip extraction complete");
                 }
+
+                string bundlePath = Path.Combine(options.ScriptPath, "worker-bundle");
+                if (Directory.Exists(bundlePath))
+                {
+                    _logger.LogInformation($"Python worker bundle detected");
+                }
             }
         }