Vulkan: Force disable broken VK_LAYER_bandicam_helper layer in editor

[akien-mga]

Fixes #101480.

For now we're only disabling it in the editor, like we've done for various other overlays which played badly with Godot's multi-window support. Not clear whether that's the problem with the Bandicam layer too, but for now I'm assuming it is.

If users report that exported games crash because of Bandicam, we can reconsider.

[bruvzg]

This completely ludicrous mess, I have installed it in a sandbox and 32-bit and 64-bit have different variable names:

Disabling all implicit layers, and keeping allowed layer list might actually be a better way to handle it.

[akien-mga]

I updated this to set both environment variables. What a mess...

Disabling all implicit layers, and keeping allowed layer list might actually be a better way to handle it.

I agree, though there's a bit more risk (we'll have to figure out what's the list of layers we want to allow - e.g. someone mentioned Valve's gamescope uses implicit layers), so probably something to iterate on during the 4.5 dev cycle.

[Repiteo]

Thanks!