[FIX] web_editor: fix layoutInfo is null traceback

When attempting to update its UI in reaction to events, summernote tries
to make layout info for the event target, this relies on finding this
information on one of the target's ancestors. In some cases, elements
can be removed from the DOM between the moment the event was triggered,
and the moment summernote attempts to create the layoutInfo, resulting
in layoutInfo being null.

This commit prevents tracebacks from happening in such cases by checking
that a layoutInfo was actually returned, and if not, aborting the UI
update that relies on it.

closes odoo/odoo#52541

X-original-commit: 3e999db0c114d51102ae51f870f98a4cc276c4b4
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/web_editor/static/lib/summernote/src/js/EventHandler.js

@@ -206,6 +206,9 @@ define([
       setTimeout(function () {
         var layoutInfo = dom.makeLayoutInfo(target);
         /* ODOO: (start_modification */
+        if (!layoutInfo) {
+            return;
+        }
         var $editable = layoutInfo.editable();
         if (event.setStyleInfoFromEditable) {
             var styleInfo = modules.editor.styleFromNode($editable);