Add basic ico support (#40822)

Closes https://github.com/zed-industries/zed/discussions/40763

<img width="867" height="1088" alt="Screenshot 2025-10-21 at 23 14 47"
src="https://github.com/user-attachments/assets/d691fb2a-afc6-4445-a335-054ef164e0d3"
/>

Also improves error handling on image open failure:

<img width="864" height="1083" alt="Screenshot 2025-10-21 at 23 14 30"
src="https://github.com/user-attachments/assets/d5388b61-995f-441b-b375-ad5136d1533b"
/>


Release Notes:

- Added basic ico support, improved unsupported image handling

crates/repl/src/outputs/image.rs

@@ -51,6 +51,7 @@ impl ImageView {
             image::ImageFormat::WebP => ImageFormat::Webp,
             image::ImageFormat::Tiff => ImageFormat::Tiff,
             image::ImageFormat::Bmp => ImageFormat::Bmp,
+            image::ImageFormat::Ico => ImageFormat::Ico,
             format => {
                 anyhow::bail!("unsupported image format {format:?}");
             }