fix: use Image.file instead of DecoratedBox and FileImage (#3606)

Co-authored-by: Alazar Genene <[email protected]>

frontend/appflowy_flutter/lib/plugins/document/presentation/editor_plugins/header/cover_editor.dart

@@ -484,14 +484,9 @@ class _ImageGridItemState extends State<ImageGridItem> {
         children: [
           InkWell(
             onTap: widget.onImageSelect,
-            child: DecoratedBox(
-              decoration: BoxDecoration(
-                image: DecorationImage(
-                  image: FileImage(File(widget.imagePath)),
-                  fit: BoxFit.cover,
-                ),
-                borderRadius: Corners.s8Border,
-              ),
+            child: ClipRRect(
+              borderRadius: Corners.s8Border,
+              child: Image.file(File(widget.imagePath), fit: BoxFit.cover),
             ),
           ),
           if (showDeleteButton)