message: fix(c-api) `wasmer_module_middleware_t` is an opaque type.
diff: @@ -98,7 +98,6 @@ impl Default for wasmer_engine_t {
  ///
  #[cfg(feature = "middlewares")]
  #[derive(Debug)]
  -#[repr(C)]
  #[allow(non_camel_case_types)]
  pub struct wasmer_module_middleware_t {
  pub(super) inner: Arc<dyn ModuleMiddleware>,
  