image loader for file:// is blocking, while image loader for http:// runs fine.

[hacknus]

Describe the bug
When using

ui.image("file://image.png");

it is blocking until the image is loaded.

But

ui.image("https://web.site.com/image.png");

will run fine and updates the GUI while the image is loading.

Expected behavior
All loaders should be non-blocking.

Desktop (please complete the following information):

• OS: macOS 14.6.1
• Version: egui 0.29

[lucasmerlin]

This should definitely be improved, I think it would be fine to just spawn a thread to load and decode the image?
Seems like someone already opened a PR: #4069
But it's stale and needs some more work before it's ready.