Update Rucio documentation copyright notice

[0xquark]

Rucio documentation still references the old copyright notice:

Copyright © 2023 CERN

This can be seen on the documentation site:
https://rucio.github.io/documentation/

The copyright notice should be updated to reflect the current year

[jainoshika]

Hi @0xquark, would it be okay to switch the footer to a dynamically generated year, e.g. Copyright © ${new Date().getFullYear()} CERN, so it stays up to date without requiring manual yearly updates?