Fix ValueNotifier example in state-management.md (#11553)

"value" and "child" were swapped in the ValueWidgetBuilder function

_Description of what this PR is changing or adding, and why:_ This is a
correction in the order of parameters passed to a function, in the
ValueNotifier usage example.

_Issues fixed by this PR (if any):_ 
![Screenshot 2024-12-27
223344](https://github.com/user-attachments/assets/b1c1603c-19f2-4be8-b8f3-cb52a3d8e380)

src/content/get-started/fundamentals/state-management.md

@@ -354,7 +354,7 @@ Column(
   children: [
     ValueListenableBuilder(
       valueListenable: counterNotifier,
-      builder: (context, child, value) {
+      builder: (context, value, child) {
         return Text('counter: $value');
       },
     ),