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

Reviewed-on: #64

lib/models/requests/paginate.dart

@@ -1,14 +1,16 @@
 import "package:freezed_annotation/freezed_annotation.dart";
+
 part "paginate.freezed.dart";
 part "paginate.g.dart";
 
-@freezed
-abstract class PaginateRequest with _$PaginateRequest {
-  const factory PaginateRequest({
-    required String roomId,
-    required int? maxTimelineId,
-    @Default(20) int limit,
-  }) = _PaginateRequest;
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable()
+class const PaginateRequest({
+  required final String roomId,
+  required final int? maxTimelineId,
+  final int limit = 20,
+}) with _$PaginateRequest {
+  Map<String, Object?> toJson() => _$PaginateRequestToJson(this);
 
   factory PaginateRequest.fromJson(Map<String, Object?> json) =>
       _$PaginateRequestFromJson(json);