Add pin for eigen-abi-devel to 3.4.0

[traversaro]

The eigen package is a bit a peculiar case of header-only library that is extensively used in the ABI interface of compiled libraries. To handle this, after the discussion in conda-forge/eigen-feedstock#49, we added a eigen-abi-devel package to track the ABI used in downstream packages.

To permit migrations of packages that depend on eigen on their ABI, this PR adds a pinning of eigen-abi-devel to 3.4.0 (the version of Eigen used in conda-forge since 2021 and until now).

xref: conda-forge/eigen-feedstock#52

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

[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 (recipe/meta.yaml) and found it was in an excellent condition.

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

For recipe/meta.yaml:

• ℹ️ The recipe is not parsable by parser conda-recipe-manager. The recipe can only be automatically migrated to the new v1 format if it is parseable by conda-recipe-manager.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/22298373824. Examine the logs at this URL for more detail.}