Add dates of successful qt5 dependency updates to blacklisted dashboard

It would be nice to see dates of dependency updates in qt5 project in the blacklisted dash board, https://testresults.qt.io/grafana/d/000000022/coin-blacklisted-tests?orgId=1
Because it is not until a dependency update when a number of blacklisted can change.

Number of daily builds on the other hand doesn't see relevant in this dashboard.