qt5 dev CI is blocked

Provisioning is repeatedly failing with

Failed to provision template 'qtci-macos-10.14-x86_64-6aa4bf'

AgentException: 'Provisioning failed, it is likely to be a script failure. Read the log for details and try to fix the issue.'

This is preventing the emsdk version upgrade from being merged, which we would like to have in place for beta 3. See https://codereview.qt-project.org/c/qt/qt5/+/420155