[glibc] contrib.texi: update

[Maciej W. Rozycki]

On Sun, 21 Jul 2024, Andreas K. Huettel wrote:

> >  Where have these entries come from anyway?  I can't see them posted to 
> > the mailing list.
> 
> For the last year I've done them as part of the release manager tasks [*],
> occasionally asking for advice in the process.

 Fair enough, but aren't the non-purely-technical changes (such as bumping 
version numbers up or adjusting dates would be) made in the course subject 
to our usual consensus rule?  I would certainly expect any updates to the 
manual to be posted and reviewed, preferably by someone who's skilled in 
writing documentation.

 NB I appreciate your effort as a release manager, thank you!

  Maciej