The VxWorks implementation of std::variant is broken.
std::visit throws std::bad_variant_access when called on a variant with
duplicated types.
Skip the tests that are affected by it.
Pick-to: 6.7
Task-number: QTBUG-115777
Change-Id: I45227cc543ef7db2217b1d53313c2e2b140988d6
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 0e9c0c0847bd09c8a2b5166a2bafc103db0d3abc)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>