Update OECD DAC Codelists with 2025-10-30 changes

[Bjwebb]

The corresponding PR for our import scripts is IATI/DAC-Codelists#14

This uses the new OECD development-finance-codelists: https://development-finance-codelists.oecd.org/CodesList.aspx

[robredpath]

@Bjwebb I'm sure I remember some conversation about the removal of activation-date="2010-01-01" but there's nothing in this conversation. Is there anything we have to say about why that change is happening?

[markbrough]

I can see that there are a number of pending changes to the IATI codelists to bring them in line with the OECD codelists, and noticed this pull request. The Aid Transparency Tracker uses iatikit, which in turn uses the codelists from the IATI website. From the IATI Dashboard, I can see that Australia, Denmark and Sweden are using the code B05, which is on the OECD codelists but not yet merged. Do you have an idea of when this PR could be merged by? Many thanks!

[robredpath]

@markbrough I expect we'll get it out in the Gazette next week with a 30 day proposal period. Assuming no objections, we should see it merged by the end of May.