Hi!

While rebuilding the python related packages against the Python 3.15rc2
version we found that rdkit only builds against the default Python
version.

This is a problem because it doesn't build the module for Python 3.15,
making packages that depend on it also unable to build for Python 3.15
(for example, mdanse).

To fix this, I've made a change that makes rdkit build against all
supported Python versions. I'm attaching a debdiff with this and the
changes made for #1146588.

I've applied the fix in the sandbox [1] to verify that both rdkit and
the packages that depend on it build successfully. Please consider
applying the patch to support the upcoming 3.15 version.

Setting the severity to important for now. Once Python 3.15 is released,
it will be added to python3-defaults and this bug will become release
critical.

Happy hacking,

[1]: https://debusine.debian.net/debian/r-python-python3.15/