[FIX] web_editor: no rerender when content is reset with empty string

This event listener was added for the `historyStep` event of the editor
in [1] as a proxy for the `input` event of the editable node. This was
wrong because the `historyStep` event is also triggered at other times
than when the user makes an input.

In particular, it is called when switching records. In such case, the
new value from props can be '' which is not suitable for edition, so
it is replaced with '<p><br></p>'. But since that happens in a function
that is going to call `_historyStep` and the editing value was just
changed to something else that the value received in props, the listener
from [1] would make it dirty and thus trigger a re-render etc.

This commit fixes the issue by modifying the listener in such a way
that it listens to the proper event it was intended to target.

[1]: f56e3bca2456f04616982a9a0e77b8d4c5a0abff

X-original-commit: 384ff11f06ba86360f1993cf0c8a17c2dbaa11de
Part-of: odoo/odoo#113811

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

@@ -314,7 +314,7 @@ export class HtmlField extends Component {
             this.wysiwyg.toolbar.$el.append($codeviewButtonToolbar);
             $codeviewButtonToolbar.click(this.toggleCodeView.bind(this));
         }
-        this.wysiwyg.odooEditor.addEventListener("historyStep", () =>
+        this.wysiwyg.odooEditor.editable.addEventListener("input", () =>
             this.props.setDirty(this._isDirty())
         );