message: fix: Make it work if `serde` is disabled.
diff: @@ -31,7 +31,8 @@ pub struct DataInitializer<'data> {
  /// As `DataInitializer` but owning the data rather than
  /// holding a reference to it
  -#[derive(Debug, Clone, Serialize, Deserialize)]
  +#[derive(Debug, Clone)]
  +#[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
  pub struct OwnedDataInitializer {
  /// The location where the initialization is to be performed.
  pub location: DataInitializerLocation,
  