Fix (unreported) ID copied in libs making their depencies directly linked.

Not really critical in current main, since such 'copying in library'
behavior is fairly rare, but once it start being applied to e.g.
geometry IDs owning shape keys, it would make Blender unhappy because
unlinkable IDs (the shape keys) would be tagged as directly linked.

source/blender/blenkernel/intern/lib_id.cc

@@ -638,6 +638,11 @@ static int id_copy_libmanagement_cb(LibraryIDLinkCallbackData *cb_data)
       BLI_assert(cb_data->self_id->tag & ID_TAG_NO_MAIN);
       id_us_plus_no_lib(id);
     }
+    else if (ID_IS_LINKED(cb_data->owner_id)) {
+      /* Do not mark copied ID as directly linked, if its current user is also linked data (which
+       * is now fairly common when using 'copy_in_lib' feature). */
+      id_us_plus_no_lib(id);
+    }
     else {
       id_us_plus(id);
     }