fix: intermittent "utils attribute not found" issue in webpack_loader (#37109)

xmodule/util/builtin_assets.py

@@ -5,7 +5,6 @@ These should not be used to support any XBlocks outside of edx-platform.
 """
 from pathlib import Path
 
-import webpack_loader
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 
@@ -44,6 +43,11 @@ def add_webpack_js_to_fragment(fragment, bundle_name):
     """
     Add all JS webpack chunks to the supplied fragment.
     """
-    for chunk in webpack_loader.utils.get_files(bundle_name, None, 'DEFAULT'):
+    # Importing webpack_loader.utils at the top of the module causes an exception:
+    #   OSError: Error reading webpack-stats.json.
+    #   Are you sure webpack has generated the file and the path is correct?
+    # We are not quite sure why.
+    from webpack_loader.utils import get_files
+    for chunk in get_files(bundle_name, None, 'DEFAULT'):
         if chunk['name'].endswith(('.js', '.js.gz')):
             fragment.add_javascript_url(chunk['url'])