[1.11.x] Fixed #28414 -- Fixed ClearableFileInput rendering as a subwidget of MultiWidget.

Backport of d4da39685b from master

docs/releases/1.11.4.txt

@@ -28,3 +28,10 @@ Bugfixes
 
 * Fixed ``QuerySet.count()`` for ``union()``, ``difference()``, and
   ``intersection()`` queries. (:ticket:`28399`).
+
+* Fixed ``ClearableFileInput`` rendering as a subwidget of ``MultiWidget``
+  (:ticket:`28414`). Custom ``clearable_file_input.html`` widget templates
+  will need to adapt for the fact that context values
+  ``checkbox_name``, ``checkbox_id``, ``is_initial``, ``input_text``,
+  ``initial_text``, and ``clear_checkbox_label`` are now attributes of
+  ``widget`` rather than appearing in the top-level context.

docs/spelling_wordlist

@@ -804,6 +804,7 @@ subtransactions
 subtree
 subtype
 subviews
+subwidget
 subwidgets
 superclass
 superset