Update for Flutter 3.10 beta (#1746)

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [ ] All existing and new tests are passing.

---------

Co-authored-by: David Iglesias <ditman@gmail.com>
Co-authored-by: Mark Thompson <2554588+MarkTechson@users.noreply.github.com>
Co-authored-by: John Ryan <ryjohn@google.com>

place_tracker/lib/place_list.dart

@@ -64,17 +64,11 @@ class _CategoryButton extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    late String buttonText;
-    switch (category) {
-      case PlaceCategory.favorite:
-        buttonText = 'Favorites';
-        break;
-      case PlaceCategory.visited:
-        buttonText = 'Visited';
-        break;
-      case PlaceCategory.wantToGo:
-        buttonText = 'Want To Go';
-    }
+    final buttonText = switch (category) {
+      PlaceCategory.favorite => 'Favorites',
+      PlaceCategory.visited => 'Visited',
+      PlaceCategory.wantToGo => 'Want To Go'
+    };
 
     return Container(
       margin: const EdgeInsets.symmetric(vertical: 12.0),