Builtin reverb: when used destructively, preview is not the same as the applied effect

### Bug description

This issue occurs for both mono and stereo tracks.
There is also a problem with the realtime preview of reverb for mono tracks: https://github.com/audacity/audacity/issues/3315#issuecomment-2027239760

This issue is a regression wrt Audacity 3.2.5

### Steps to reproduce

1. Generate a rhythm track with tempo 60, and 1 beat per bar.
2. Select all the audio, and open the Reverb effect from the effects menu.
3. Select the factory preset for a large room.
4. Preview the effect.
5. Apply the effect.
6. Playback the track with the effect applied.

### Expected behavior

The preview and the playback after the effect is applied should sound the same.

### Actual behavior

The preview is quieter than the playback, and also the amount of reverb is different, though the latter isn't easy to hear because of the volume difference.
Preview and playback after effect applied, as recorded by reaper (first 6 ticks are preview):

If the preview metronome ticks are amplified by 6db to make all the ticks the same amplitude, it can be seen that the amount of reverb is different:

### Audacity Version

latest stable version (from audacityteam.org/download)

### Operating system

Windows

### Additional context

_No response_