Python 3.13 addition as a supported Python version started

[Matthias Klose]

python3-defaults in unstable now adds Python 3.13 as a supported Python 
3.13 version.  You might see some additional build failures, until the 
binNMUs for this addition are done [1]. This might take some days for 
some architectures.  We will most likely also see some more issues once 
the lower levels of this addition are done.

Matthias
[1] https://release.debian.org/transitions/html/python3.13-add.html