RTR#31 Further refactoring, update Symfony to 6.4 and other deps

Today, I continue preparations for refactoring. Szymon updated the environment and added a spoiler tag in the markdown editor. Additionally, there were several fixes and improvements related to collections and the People page.

https://codeberg.org/Kbin/kbin-core/pulls/1325
https://codeberg.org/Kbin/kbin-core/pulls/1327

You can track changes in the official repository
https://codeberg.org/Kbin/kbin-core

or on Github
https://github.com/ernestwisniewski/kbin