Image error when generating preview icon for non RGBA8 terrain tiles

[SaracenOne]

Godot version

5ee9831

System information

Windows 11

Issue description

Godot editor will throw an error and fail to generate preview icons for terrain tiles which use a base image which is not RGBA8 format.
core\io\image.cpp:2788 - Condition "format != p_src->format" is true.

Steps to reproduce

• Import a non-RGBA8 image into Godot.
• Create a TileMap
• Create an associated TileSet
• Create a terrain for this tileset
• Add the image as an atlas
• Go to the paint tab
• Paint the terrain on the TileSet
• An error will occur any time terrains are edited in the TileSet editor or selected in the TileMap editor terrain tab.

Minimal reproduction project

tileset_terrain_bug.zip