git: openjdk/jfx-sandbox: tsayao_gtk4_playground: - Use POPOVER

[duke]

Changeset: 53d341de
Author:    Thiago Milczarek Sayão <thiago.sayao at gmail.com>
Date:      2021-10-06 21:15:26 +0000
URL:       https://git.openjdk.java.net/jfx-sandbox/commit/53d341de3e22b20558b39691a7e362bd01dfcf64

- Use POPOVER

! modules/javafx.graphics/src/main/native-glass/gtk4/glass_screen.cpp
! modules/javafx.graphics/src/main/native-glass/gtk4/glass_window.cpp