Publish docs and playground on `cargo-dist` release (#12079)
## Summary
These are now `post-announce-jobs`. So if they fail, the release itself
will still succeed, which seems ok. (If we make them `publish-jobs`,
then we might end up publishing to PyPI but failing the release itself
if one of these fails.)
The intent is that these are still runnable via `workflow_dispatch` too.
Closes https://github.com/astral-sh/ruff/issues/12074.
