Use pre-build builds for metatensor

[PicoCentauri]

Using builds from https://luthaf.fr/nightly-wheels/ for the speading up the builds and allowing easier downstream usage. The makes the infrastructure code also much cleaner.

The env variable PIP_EXTRA_INDEX_URL=https://luthaf.fr/nightly-wheels/ for RTD is set in their web interface because setting them in yml file is for whatever reasons not working...

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📚 Documentation preview 📚: https://equisolve--53.org.readthedocs.build/en/53/

[agoscinski]

With the nightly wheels we also are on a rolling release, because we do not set the version. We would need to get the dev version that corresponds to commit c022fde. That would be dev305
(You can see it in the wheels https://github.com/lab-cosmo/equistore/actions/runs/5478799015 )

At the moment nightly wheels only supports the most recent version, so we cannot download older versions. But once this is available it should a bit look like this

pip install --pre --extra-index-url https://luthaf.fr/nightly-wheels/ equistore-core==0.1.0.dev316
# we need --no-deps because equistore depends on equistore-core and then the version resolvement does not work
pip install --pre --extra-index-url https://luthaf.fr/nightly-wheels/ --no-deps equistore==0.1.0.dev3016

I am also okay if we just use the nightly wheel as new standard version for all packages until we automatize the nightly wheels. But then we need to coordinate the nightly wheels release for rascaline and equisolve (and maybe torch_spex). What do you think?

[PicoCentauri]

Agreeing on general nightly builds would be nice. I don't if can manage to keep up with the changes in all our substream packages....

EDIT: In the cookbook we already rely on the latest nightly build so maybe we can also here...

[agoscinski]

In the cookbook we already rely on the latest nightly build so maybe we can also here...

In the cookbook I also did not like this decision so much, but since we have many dependencies I wanted to keep the building time a low as possible by using prebuilts. When we have a metatensor release with prebuilts, I am thinking to change it to the latest release of metatensor.