Additional Fields to Collect cannot be set read-only at creation

**Describe the bug**
When adding "Attendees' data to collect", only a **Required** checkbox is available.
After creation, when you edit a field a **Read Only** checkbox is available.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to Event detail
2. Click on 'Attendees' data to collect'
3. Scroll down to 'add new' and click
4. See dialog without **Read Only** checkbox
5. Fill fields (One choice list (radio button)) and save
6. Click on 'edit' of above created field
7. See dialog with **Read Only** checkbox

**Expected behavior**
Checkbox **Read only** in field creation dialog

**Screenshots**
Creation dialog checkboxes
Edit dialog after field creation and the shown checkboxes

**Desktop (please complete the following information):**
- OS: Windows 10
- Browser Firefox
- Version 121.0

**Additional context**
Docker Image Alf.io v.2.0-M4-2402-3 (non-dev)