There are some issues with checkboxes that belong to ezmatrix in the content type.

Steps to reproduce

1. Install Ibexa DXP v4.5
2. Create a content type with ezmatrix field and add two rows
3. Save the content type and edit it again
4. Select the checkbox in the header
5. Check the delete button - it's still disabled
6. Uncheck one checkbox and check again to activate the delete button
7. Delete all rows
8. Add a new row

Result

Checking all checkboxes using the checkbox in the header does not activate the delete button.
After removing rows, the checkbox in the header remains selected and does not affect newly added checkboxes.

Expected result

After checking the checkbox in the header, the delete button should become active. Once removed, the header should also disappear or the checkbox should be unchecked automatically and affect newly added rows