remove project specific reports from website

[Gigaszi]

Description

Remove the project specific reports from the website.

Corresponding issue

Closes #318

New or changed dependencies

• None

Checklist

• I have updated my branch to main (e.g. through git rebase main)
• My code follows the style guide and was checked with pre-commit before committing
• I have commented my code
• I have added sufficient unit and integration tests
• I have updated the CHANGELOG.md

[matthiasschaub]

Those changes should probably be listed in the Changelog under "Breaking Changes" and a note und "How to upgrade" saying as much as:
"Reports [name of the reports] are not accessibly via the website anymore. If you want to access those reports please use the API."