CI fails on MacOS with "clang cannot compile programs"

Since 5 days ago, our CI has started to [fail on MacOS](https://github.com/scikit-image/scikit-image/actions/runs/8865314050/job/24341444497#step:5:208) with
```
  ../meson.build:1:0: ERROR: Compiler /usr/bin/clang cannot compile programs.
```
which doesn't make sense to me (yet). Unsure if that message is caused by something else..