[FIX] web_editor: prevent <li> in <td>

When converting a list-group to a table, we sometimes ended up with <li>
in <td> element, which is non-sense and is hereby corrected.

X-original-commit: 41eda109d2fbc0eb6616fb03102a205b945ab9b2
Part-of: odoo/odoo#81540

addons/web_editor/static/src/js/backend/convert_inline.js

@@ -606,6 +606,8 @@ function listGroupToTable($editable) {
                 $row.append($col);
                 $table.append($row);
                 $(child).remove();
+            } else if (child.nodeName === 'LI') {
+                $table.append(...child.childNodes);
             } else {
                 $table.append(child);
             }