Force siphash24 hash algorithm when cross-compiling

[gmarkall]

When cross-compiling, the hash function is forced to be FNV because the configure script defines HAVE_ALIGNED_REQUIRED which is then used by pyhash.h to change the default to FNV (see #718).

This PR fixes the issue by specifying siphash24 to the configure script when cross-compiling. With this PR, I now get:

$ python -c "import sys; print(sys.hash_info.algorithm)"
siphash24

instead of

$ python -c "import sys; print(sys.hash_info.algorithm)"
fnv

I'm not that familiar with the setup of this feedstock so I don't know if this is an appropriate solution or more of a sketch of a solution - any feedback / guidance is appreciated!

Checklist

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

[gmarkall]

@conda-forge-admin, please rerender

[github-actions[bot]]

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.

[isuruf]

Can you add a test?