scripting: [deprecation] show() in Window has been deprecated

Change-Id: I1c157ebbfa0c307fd92c0a2d26e7d530be8ea9da
Reviewed-on: https://gerrit.libreoffice.org/11437
Reviewed-by: Thomas Arnhold <thomas@arnhold.org>
Tested-by: Thomas Arnhold <thomas@arnhold.org>