Preparation for 2024 edition

Enable and apply 2024 compat lints. It should be possible to merge this before converting to 2024.

This ignores the gen keyword lint which we will need to address by updating rand and renaming world::gen. But those can be in separate MRs. The remaining allowed lints are changes we don't need to apply.

• By opening this merge request, you agree to release your code and all other changes under the GPL 3 license and to abide by the terms set by this license.
• Migrations have been added if applicable (migrations are always necessary for removing/renaming item asset files)
• Significant changes of this merge request have been added to the changelog.