fixed window transparency

[mgalos999]

fixes https://github.com/rust-windowing/winit/issues/2502

[stefnotch]

This seems to make borderless, transparent windows invisible for me. (Using winit v0.28.6 as a base)

[TeamDman]

This seems to make borderless, transparent windows invisible for me. (Using winit v0.28.6 as a base)

Is that not the expected behaviour for a transparent window?

[TeamDman]

can confirm it makes everything transparent, not just the parts that should be transparent lol

(used cargo patch to try this PR in my project, the main window should be where the outline is but it is entirely invisible)

[danielnehrig]

is there any issues with this pr ? looking forward to that working.