Draft: Ensure package files are removed when project is destroyed

What does this MR do and why?

When you delete a project, the package files are not removed. This bug was already addressed in #288834 and tried to be solved in MR !48767 (closed). Unfortunately, the MR was then closed because it was dormant for several months.

But now it's time to finally solve this problem with this MR.

Solves #288834

🛠 with ❤ at Siemens

/cc @bufferoverflow

How to set up and validate locally

See #288834

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.