Fix performance regression in bundle module for non-Darwin targets.
Fix performance regression in bundle module for non-Darwin targets.

The Probe and the validate script only need to be run for the platforms
that actually support bundles.

Change-Id: Ib56eb28c8b036d52d97c85345547060bb470d67b
Reviewed-by: Jake Petroules <2d627e1cecd5435752fa500bacbe05f7cc90c369@theqtcompany.com>

qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs