Extend the deployment workflows to generate the changelog files

Description
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Needs: All other issues of https://github.com/FAForever/fa/issues/6236

This is where we combine everything together! We can use the [deployment workflow](https://github.com/FAForever/fa/actions/workflows/update-fafdevelop.yaml) to not just deploy, but also generate the changelog files using the other Github actions, store them where the game (Lua) expects them to be and push the content to `deploy/fafdevelop` (and in the near future: also to `deploy/fafbeta`).

Once this issue is completed we have the basic framework with always up to date changelogs, including the current open changes.

We can then start introducing additional features to enhance the experience for the user, of which there are plenty to think of!