Recreate auto-setup.cmake upon cleaning

Currently when Qt Creator cleans build files it doesn't clean
<build-dir>/.qtc/package-manager/auto-setup.cmake 
and this caused an issue when switching between versions. 

In my particular case it had to do with this:

https://codereview.qt-project.org/c/qt-creator/qt-creator/+/538496

I built my project and started using conan afterwards. Subsequently I ran into this issue and installed Qt Creator 13.0.0 and cleaned the build, but because it doesn't clean this file, I had to go and delete it manually.