mod: color alpha

`withOpacity` -> `withValues`

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/pages/subscription_detail/view.dart

@@ -102,7 +102,8 @@ class _SubDetailPageState extends State<SubDetailPage> {
                 decoration: BoxDecoration(
                   border: Border(
                     bottom: BorderSide(
-                      color: Theme.of(context).dividerColor.withOpacity(0.2),
+                      color:
+                          Theme.of(context).dividerColor.withValues(alpha: 0.2),
                     ),
                   ),
                 ),