This fixes the flushing with external textures. We don't know if we need to flush synchronously with multiple contexts, so I removed that. Acked-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com> Reviewed-by: Adam Jackson <ajax@redhat.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11341>