The changelog for an empty version will now be:
```
No user facing changes.
```
And this will appear in the final changelog when there is an actual release.
The benefits are that users will see regular release cycles and know
how old versions are even if there's no changes for a particular version
If we find that we are going months without any user facing changes, but
we have non-visible changes, then we can rethink this strategy.
But I think this is nicer than having empty sections for a version.
This change ensures that the the script can handle
commits with no committer in them. This will happen
for some commits that are auto-generated during
PRs.
This commit ensures that the changelog is updated before a release with
the correct date and version.
Also, after a release, a mergeback PR is created to ensure that the
changelog update and version bump is available in main.
Fix a minor issue in the update-release-branch.py script that performs a
call to `sorted` but doesn't use the output. Since `sorted` does not
operate in place, the call is currently useless. As a result, the function
`get_pr_for_commit` does not currently work as exected. I.e. it is
expected to return the "first" (i.e. lowest PR number), but actually it
returns the first in the list provided by GitHub.
