docs: update copyright year

[trueNAHO]

Description

Despite the year 2025 being less than two months away, this patch updates the copyright year to 2024.

The copyright year of the license was updated every year, except in 2021:

1. 9d3d742 ("license: bump year")
2. e15cd64 ("Update LICENSE file for 2019")
3. 03b622b ("Bump copyright year")
4. acad715 ("docs: update copyright year")
5. b2a6cf7 ("docs: update copyright examples/years")

Checklist

• Change is backwards compatible.

• Code formatted with ./format.

• Code tested through nix-shell --pure tests -A run.all or nix develop --ignore-environment .#all using Flakes.

• Test cases updated/added. See example.

• Commit messages are formatted like

  {component}: {description}
  
  {long description}
  

  See CONTRIBUTING for more information and recent commit messages for examples.

• If this PR adds a new module

  • Added myself as module maintainer. See example.

Maintainer CC

@rycee