fix(ui_auth): fix confirmation dialog for delete account button (#346)

Co-authored-by: russellwheatley <[email protected]>

Author: TimBaumgart

packages/firebase_ui_auth/lib/src/widgets/delete_account_button.dart

@@ -82,7 +82,8 @@ class _DeleteAccountButtonState extends State<DeleteAccountButton> {
   fba.FirebaseAuth get auth => widget.auth ?? fba.FirebaseAuth.instance;
   bool _isLoading = false;
 
-  void Function() pop<T>(T result) => () => Navigator.of(context).pop(result);
+  void Function() pop<T>(BuildContext context, T result) =>
+      () => Navigator.of(context).pop(result);
 
   Future<void> _deleteAccount() async {
     bool? confirmed = !widget.showDeleteConfirmationDialog;
@@ -94,8 +95,8 @@ class _DeleteAccountButtonState extends State<DeleteAccountButton> {
         context: context,
         builder: (context) {
           return UniversalAlert(
-            onConfirm: pop(true),
-            onCancel: pop(false),
+            onConfirm: pop(context, true),
+            onCancel: pop(context, false),
             title: l.confirmDeleteAccountAlertTitle,
             confirmButtonText: l.confirmDeleteAccountButtonLabel,
             cancelButtonText: l.cancelButtonLabel,