"Get more effects" not present in relevant menus

### Bug description

_No response_

### Steps to reproduce

Look for "Get more effects..." in the menus they're supposed to be in

### Expected behavior

The menu item is in the realtime effects and the main Effect menu

### Actual behavior

It is not.

### Audacity Version

Audacity 4.0 beta 2

### Operating system

Windows, MacOS

### Additional context

_No response_

Start by reproducing the missing menu item in Audacity 4.0 beta 2 on Windows or macOS, checking the realtime effects menu and the main Effect menu. Trace where those menus are constructed; done when “Get more effects...” appears in both expected locations.

Written by the indexing model from the issue text.