How to delete programs from "Edit In"

To expand on the reply from Ken-

1) Select the Additional External Editor Preset you want to remove from Edit-In.  In the [Preset] disclosure arrow menu.

2) Click the disclosure arrow menu a second time and choose the 'Delete...' option-

Alternately-  You can use Windows File Explorer to delete the Preset in the {...\\Lightroom\\External Editor Presets} folder, and restart Lr-Classic.

C:\\Users\\{YourName}\\AppData\\Roaming\\Adobe\\Lightroom\\External Editor Presets

Preferences -> External Editing - You can make changes there.