Add null-safety for list props with type dynamic

lib/features/mailbox/domain/state/create_new_mailbox_state.dart

@@ -24,5 +24,5 @@ class CreateNewMailboxFailure extends FeatureFailure {
   CreateNewMailboxFailure(this.exception);
 
   @override
-  List<Object> get props => [exception];
+  List<Object?> get props => [exception];
 }

lib/features/mailbox/domain/state/delete_multiple_mailbox_state.dart

@@ -46,5 +46,5 @@ class DeleteMultipleMailboxFailure extends FeatureFailure {
   DeleteMultipleMailboxFailure(this.exception);
 
   @override
-  List<Object> get props => [exception];
+  List<Object?> get props => [exception];
 }

lib/features/mailbox/domain/state/get_all_mailboxes_state.dart

@@ -21,5 +21,5 @@ class GetAllMailboxFailure extends FeatureFailure {
   GetAllMailboxFailure(this.exception);
 
   @override
-  List<Object> get props => [exception];
+  List<Object?> get props => [exception];
 }

lib/features/mailbox/domain/state/mark_as_mailbox_read_state.dart

@@ -73,5 +73,5 @@ class MarkAsMailboxReadFailure extends FeatureFailure {
   MarkAsMailboxReadFailure(this.exception);
 
   @override
-  List<Object> get props => [exception];
+  List<Object?> get props => [exception];
 }

lib/features/mailbox/domain/state/move_mailbox_state.dart

@@ -39,5 +39,5 @@ class MoveMailboxFailure extends FeatureFailure {
   MoveMailboxFailure(this.exception);
 
   @override
-  List<Object> get props => [exception];
+  List<Object?> get props => [exception];
 }

lib/features/mailbox/domain/state/refresh_changes_all_mailboxes_state.dart

@@ -21,5 +21,5 @@ class RefreshChangesAllMailboxFailure extends FeatureFailure {
   RefreshChangesAllMailboxFailure(this.exception);
 
   @override
-  List<Object> get props => [exception];
+  List<Object?> get props => [exception];
 }

lib/features/mailbox/domain/state/rename_mailbox_state.dart

@@ -21,5 +21,5 @@ class RenameMailboxFailure extends FeatureFailure {
   RenameMailboxFailure(this.exception);
 
   @override
-  List<Object> get props => [exception];
+  List<Object?> get props => [exception];
 }

lib/features/mailbox/domain/state/search_mailbox_state.dart

@@ -19,5 +19,5 @@ class SearchMailboxFailure extends FeatureFailure {
   SearchMailboxFailure(this.exception);
 
   @override
-  List<Object> get props => [exception];
+  List<Object?> get props => [exception];
 }