PluginSidebar / Plugins do not work in Widget Editor #65714

Description

Plugins , and therefore PluginSidebars, do not render in the Widget Block Editor.

They can be seen in wp.plugins.getPlugins, but they are not rendered in the menu or as any pinned items. The same plugins rendered as expected in a Post Block Editor.

Step-by-step reproduction instructions

This can be reproduced with this simple plugin based on Gutenberg documentation. The below plugin will register but nothing is output.

import { PluginSidebar } from '@wordpress/edit-post';
import { registerPlugin } from '@wordpress/plugins';
import { useState } from '@wordpress/element';

const PluginSidebarExample = () => {
	return (
		<PluginSidebar
			name="plugin-sidebar-example"
			title={'My PluginSidebar'}
			icon={ 'smiley' }
		>hello</PluginSidebar>
	);
};

// Register the plugin
registerPlugin( 'plugin-sidebar-example', { render: PluginSidebarExample } );

editPost exists in the wp object in the Widget Block Editor context. For what it's worth there isn't a PluginSidebar on the editWidgets object like there is for editSite

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes