Adding horovod

[njzjz]

Resolves #6228.

Checklist

• Title of this PR is meaningful: e.g. "Adding my_nifty_package", not "updated meta.yaml".
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[conda-forge-webservices]

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/horovod) and found some lint.

Here's what I've got...

For recipes/horovod:

• Failed to even lint the recipe, probably because of a conda-smithy bug 😢. This likely indicates a problem in your meta.yaml, though. To get a traceback to help figure out what's going on, install conda-smithy and run conda smithy recipe-lint . from the recipe directory.

[conda-forge-webservices]

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/horovod) and found it was in an excellent condition.

[conda-forge-webservices]

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/horovod) and found some lint.

Here's what I've got...

For recipes/horovod:

• The requirements section contained an unexpected subsection name. ignore_run_exports_from is not a valid subsection name.
• The requirements section contained an unexpected subsection name. missing_dso_whitelist is not a valid subsection name.

[conda-forge-webservices]

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/horovod) and found it was in an excellent condition.

[njzjz]

@conda-forge-admin please restart ci

[njzjz]

@conda-forge/help-python-c ready for review.

The package is built against both tensorflow and pytorch, but one is free to install only one of them.

[xhochy]

Please add a comment here why they are listed.

[njzjz]

Added. Thanks for the review.

[conda-forge-webservices]

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/horovod) and found some lint.

Here's what I've got...

For recipes/horovod:

• Failed to even lint the recipe, probably because of a conda-smithy bug 😢. This likely indicates a problem in your meta.yaml, though. To get a traceback to help figure out what's going on, install conda-smithy and run conda smithy recipe-lint . from the recipe directory.

[conda-forge-webservices]

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/horovod) and found it was in an excellent condition.