Hi!

While rebuilding the python related packages against the Python 3.15rc2
version we found that dask.distributed fails to build from source [1].

The problem is that tests timeout, caused by some flaky tests. And the
solution is to adjust timeouts and retries for those flaky tests.

I've applied this fix in the sandbox [2] to verify that it builds
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/artifact/4524709/
[2]: https://debusine.debian.net/debian/r-python-python3.15/