replace deprecated show_uri with async UriLauncher
Since GTK 4.10, show_uri is deprecated. Therefore, it should be replaced with UriLauncher. That is also a great opportunity to fix the fixmes asking for logging of URI launch failures.
Since GTK 4.10, show_uri is deprecated. Therefore, it should be replaced with UriLauncher. That is also a great opportunity to fix the fixmes asking for logging of URI launch failures.