misc: always set render_skeleton template variable (#29151)

combo/public/templatetags/combo.py

@@ -45,6 +45,8 @@ def skeleton_text(context, placeholder_name, content=''):
 @register.inclusion_tag('combo/placeholder.html', takes_context=True)
 def placeholder(context, placeholder_name, **options):
     placeholder = Placeholder(key=placeholder_name, cell=context.get('cell'), **options)
+    # make sure render_skeleton is available in context
+    context['render_skeleton'] = context.get('render_skeleton')
     if context.get('placeholder_search_mode'):
         if placeholder.name:
             # only include placeholders with a name