Windows provisioning script non zero exit code not considered failure

https://ci-files01-hki.ci.qt.io:8081/coin/api/log/provisioning/qtci-windows-11_22H2-x86_64-51-e56e82/provision_1708514544/log.txt.gz

Provisioning should stop when ffmpeg fails to install, but continues.

Reason is that it does not cause powershell error/exception but rather just exits 1 and that is not separately checked and is not catched by errorActionPreference.