Move to Flutter 3.47, use the improvements that come with this (#64)

Reviewed-on: #64

lib/models/space_edge.dart

@@ -1,13 +1,15 @@
 import "package:freezed_annotation/freezed_annotation.dart";
+
 part "space_edge.freezed.dart";
 part "space_edge.g.dart";
 
-@freezed
-abstract class SpaceEdge with _$SpaceEdge {
-  const factory SpaceEdge({
-    required String childId,
-    @Default(false) bool suggested,
-  }) = _SpaceEdge;
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable()
+class const SpaceEdge({
+  required final String childId,
+  final bool suggested = false,
+}) with _$SpaceEdge {
+  Map<String, Object?> toJson() => _$SpaceEdgeToJson(this);
 
   factory SpaceEdge.fromJson(Map<String, Object?> json) =>
       _$SpaceEdgeFromJson(json);