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

Reviewed-on: #64

lib/models/requests/download_media.dart

@@ -1,15 +1,17 @@
 import "package:freezed_annotation/freezed_annotation.dart";
+
 part "download_media.freezed.dart";
 part "download_media.g.dart";
 
-@freezed
-abstract class DownloadMediaRequest with _$DownloadMediaRequest {
-  const factory DownloadMediaRequest({
-    required Uri mxc,
-    @Default(false) bool encrypted,
-    @Default(false) bool isAvatar,
-    @Default(false) bool thumbnailAvatar,
-  }) = _DownloadMediaRequest;
+@Freezed(toJson: false, fromJson: false)
+@JsonSerializable()
+class const DownloadMediaRequest({
+  required final Uri mxc,
+  final bool encrypted = false,
+  final bool isAvatar = false,
+  final bool thumbnailAvatar = false,
+}) with _$DownloadMediaRequest {
+  Map<String, Object?> toJson() => _$DownloadMediaRequestToJson(this);
 
   factory DownloadMediaRequest.fromJson(Map<String, Object?> json) =>
       _$DownloadMediaRequestFromJson(json);