Changelog was not updated in the last release

[blakeli0]

CHANGELOGs in each module was not updated since the March release. For example, CHANGELOG.md in java-spanner .

This is likely due to the releases (1.83 to 1.85) was manually performed through release-please cli and didn't trigger the changelog generation logic.

There are three aspects we want to fix:

1. Manually re-run the changelog generation CI with all the commit history to populate the CHANGELOG for last release.
2. Make sure the changelog generation logic works for recently migrated repos.
3. Make sure the changelog generation logic works for releases performed from release-please cli as well. Or provide a way to manually trigger it.

[meltsufin]

The root CHANGELOG.md seems to have been updated. The issue is that the changes were not distributed to the modules.

We can try to redistribute the changes to individual module CHANGELOG.mds, but how important is it?

The release notes for the Libraries BOM are probably more important, and I'm not sure what's going on there. Those don't look complete for the last few releases either: https://github.com/googleapis/java-cloud-bom/releases.