Fix #91966: Alembic/USD export ignores bone parent animation

For non-object parents (so bones & vertices), the parent is now also
explicitly checked for animation. In other words: having an animated
parent will cause the transform of the child to be written to Alembic/USD
on every frame (as if it is animated itself).

source/blender/io/common/intern/abstract_hierarchy_iterator.cc

@@ -485,6 +485,12 @@ void AbstractHierarchyIterator::context_update_for_graph_index(
 {
   /* Update the HierarchyContext so that it is consistent with the graph index. */
   context->export_parent = graph_index.object;
+
+  /* If the parent type is such that it cannot be exported (at least not currently to USD or
+   * Alembic), always check the parent for animation. */
+  const short partype = context->object->partype & PARTYPE;
+  context->animation_check_include_parent |= ELEM(partype, PARBONE, PARVERT1, PARVERT3, PARSKEL);
+
   if (context->export_parent != context->object->parent) {
     /* The parent object in Blender is NOT used as the export parent. This means
      * that the world transform of this object can be influenced by objects that