feat: support for previewing avif images in attachments (halo-dev#6446)

#### What type of PR is this?

/kind feature
/area ui
/milestone 2.19.x

#### What this PR does / why we need it:

支持在附件库中预览 `image/avif` 的图片。

#### Which issue(s) this PR fixes:

Fixes halo-dev#6320 

#### Does this PR introduce a user-facing change?
```release-note
支持在附件库中预览 avif 类型的图片
```

ui/src/utils/image.ts

@@ -5,6 +5,7 @@ export const imageTypes: string[] = [
   "image/gif",
   "image/webp",
   "image/svg+xml",
+  "image/avif",
 ];
 
 export function isImage(mediaType: string | undefined): boolean {