CI: Installing qml_formatter fails with "Executable `rustup` not found"

### Bug Description

All recent CI builds of various PRs for 2.4/Main fail:
![grafik](https://user-images.githubusercontent.com/64457745/226109088-716d721a-5167-48a4-a133-af8a6cf43416.png)

for example: https://github.com/mixxxdj/mixxx/actions/runs/4455587774/jobs/7825486519?pr=10989

### Version

2.4.0/Main

### OS

Pre-Commit