Unable to delete Tiles from Tile Palette permanently with the Delete key

Steps to reproduce:

1. Create and open a new 2D project
2. Create and open a new Tile Palette
3. Import any image into the Tile Palette window
4. Switch to the Select tool
5. Select the tile
6. Press the Delete key
7. Press CTRL+S (if the scene is dirty) or reload the Tile Palette window from the hamburger menu
8. Observe the TilePalette window

Actual results: The tile comes back after reloading the window

Expected results: The tile is permanently deleted from the Tile Palette

Reproducible with versions: 3.0.3 (2023.1.0a10), 4.1.0 (6000.0.75f1), 6.0.2 (6000.3.15f1), 7.0.1 (6000.4.7f1), 8.0.2 (6000.5.0b7, 6000.6.0a4)

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• Only the Erase tool removes the tiles permanently
• Sometimes the tiles cannot be deleted when the Tile Palette is not in edit mode. To enable it, click on the pencil icon to the right of the canvas.