fix: update collapse props

lib/widgets/files_item.dart

@@ -27,7 +27,7 @@ class FilesItem extends StatelessWidget {
     final theme = Provider.of<ThemeModel>(context);
     final codeProvider = Provider.of<CodeModel>(context);
     return AntCollapse(
-      activeKey: const [''],
+      activeKey: const {},
       onChange: (_) {
         // TODO: set active
       },

lib/widgets/release_item.dart

@@ -80,7 +80,7 @@ class _ReleaseItemState extends State<ReleaseItem> {
           const SizedBox(height: 10),
         ],
         AntCollapse(
-          activeKey: _isExpanded ? [''] : [],
+          activeKey: _isExpanded ? {''} : {},
           onChange: (_) {
             setState(() {
               _isExpanded = !_isExpanded;