Preserves the aspect ratio of its child.
The frame can respect the aspect ratio of the child widget, or use its own aspect ratio.
`GtkAspectFrame` uses a CSS node with name `aspectframe`.
Until GTK 4.10, `GtkAspectFrame` used the [enum@Gtk.AccessibleRole.group] role.
Starting from GTK 4.12, `GtkAspectFrame` uses the [enum@Gtk.AccessibleRole.generic] role.