Carousell not working with html-Element

# Bug Report

## Prerequisites

* [ x] Can you reproduce the problem on TYPO3 v11.5 LTS

* [ ] Did you [perform a cursory search](https://github.com/issues?q=is%3Aissue+user%3Abenjaminkott+repo%3Abenjaminkott%2Fbootstrap_package)
to see if your bug or enhancement is already reported?

## Description

Create an carousel element as HTML , wrote this code:

after saving this code is shown:

<iframe src="fileadmin/pano1/Pano1.html" height="600" class="tour" style="border:0; width:100%" allowfullscreen></iframe>

Same with bootstrap_package 13 + 14

Start by reproducing the issue in a TYPO3 v11.5 installation using an HTML carousel element and the provided iframe markup. Trace how the element processes and saves HTML, then verify that the iframe is rendered as HTML rather than escaped text; no specific files or tests are named in the report.

Written by the indexing model from the issue text.