style: rm trailing whitespace

Author: kdmccormick

cms/djangoapps/contentstore/views/preview.py

@@ -204,12 +204,12 @@ def _prepare_runtime_for_preview(request, block):
     # Studio ModuleStoreRuntimes, then add it to load_services_for_studio.
     # HISTORICAL CONTEXT: Until Ulmo, the `block.runtime._services.update(service)` call below would
     # actually update the services dictionary for all runtimes, as `_services` was aliased between them.
-    # This caused a grading bug, under certain conditions, so it was fixed 
+    # This caused a grading bug, under certain conditions, so it was fixed
     # in https://github.com/openedx/openedx-platform/pull/37825; now, every runtime gets a fresh,
     # independent copy of `_services`. That's good, except that some Studio code had become dependent
     # on the bugged behavior and thus expected the "preview" services below to be present in all Studio runtimes.
     # We fixed the known instance of that bugged assumption here: https://github.com/openedx/openedx-platform/pull/37900.
-    # This comment is left here as a note for future devs investigating similar bugs. 
+    # This comment is left here as a note for future devs investigating similar bugs.
     services = {
         "studio_user_permissions": StudioPermissionsService(request.user),
         "i18n": XBlockI18nService,