[FIX] web_editor: Html Field in Record

Using the web_editor html field in the Record component causes crashes.

Why does this happen?
The fields used in the Record component do not always have modifiers.

Solution:
Use the isReadonly function of the record to know if the field is
readonly or not.

closes odoo/odoo#113072

X-original-commit: 5354321877b65d577c419255ce43806f648e1708
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>

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

@@ -141,7 +141,7 @@ export class HtmlField extends Component {
                         // Ensure all external links are opened in a new tab.
                         retargetLinks(this.readonlyElementRef.el);
 
-                        const hasReadonlyModifiers = Boolean(this.props.record.activeFields[this.props.fieldName].modifiers.readonly);
+                        const hasReadonlyModifiers = Boolean(this.props.record.isReadonly(this.props.fieldName));
                         if (!hasReadonlyModifiers) {
                             const $el = $(this.readonlyElementRef.el);
                             $el.off('.checklistBinding');