Add Python bindings for metatensor-torch

[PicoCentauri]

This PR adds the Python bindings for the metatensor-torch library. The native library for metatensor-torch is already available at https://github.com/conda-forge/libmetatensor-torch-feedstock/blob/main/recipe/meta.yaml. The naming convention of this package is according to the discussion on conda-forge/metatensor-feedstock#2

Checklist

• Title of this PR is meaningful: e.g. "Adding my_nifty_package", not "updated meta.yaml".
• License file is packaged (see here for an example).
• Source is from official source.
• Package does not vendor other packages. (If a package uses the source of another package, they should be separate packages or the licenses of all packages need to be packaged).
• If static libraries are linked in, the license of the static library is packaged.
• Package does not ship static libraries. If static libraries are needed, follow CFEP-18.
• Build number is 0.
• A tarball (url) rather than a repo (e.g. git_url) is used in your recipe (see here for more details).
• GitHub users listed in the maintainer section have posted a comment confirming they are willing to be listed there.
• When in trouble, please check our knowledge base documentation before pinging a team.

[github-actions]

Hi! This is the staged-recipes linter and I found some lint.

File-specific lints and/or hints:

• recipes/metatensor-torch/meta.yaml:
  • lints:
    • The following maintainers have not yet confirmed that they are willing to be listed here: Luthaf. Please ask them to comment on this PR if they are.

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/metatensor-torch/meta.yaml) and found it was in an excellent condition.

[Luthaf]

Happy to help maintaining this package!

[github-actions]

Hi! This is the staged-recipes linter and your PR looks excellent! 🚀

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipes/metatensor-torch/meta.yaml) and found some lint.

Here's what I've got...

For recipes/metatensor-torch/meta.yaml:

• ❌ requirements: host: libmetatensor-torch == 0.7.3 should not contain a space between relational operator and the version, i.e. libmetatensor-torch ==0.7.3

For recipes/metatensor-torch/meta.yaml:

• ℹ️ top-level output has some malformed specs:

• In section host: libmetatensor-torch == 0.7.3 Requirements spec fields should always be space-separated to avoid known issues in conda-build. For example, instead of name =version=build, use name version build`.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/13681946728. Examine the logs at this URL for more detail.}

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/metatensor-torch/meta.yaml) and found it was in an excellent condition.

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/metatensor-torch/meta.yaml) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipes/metatensor-torch/meta.yaml:

• ℹ️ top-level output has some malformed specs:

• In section host: pytorch =*=cpu* Requirements spec fields should always be space-separated to avoid known issues in conda-build. For example, instead of name =version=build, use name version build`.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/13685213016. Examine the logs at this URL for more detail.}

[PicoCentauri]

@conda-forge/help-python-c this PR is ready for review