Add `sysroot` to `requirements/build`

[jakirkham]

In PR ( https://github.com/conda-forge/openmpi-feedstock/pull/121 ), the linux-64 builds were updated to an image based on CentOS 7, which was mentioned here ( https://github.com/conda-forge/openmpi-feedstock/pull/121#discussion_r1443658627 ). However the packages don't currently factor this into the __glibc version constraint

This PR fixes that by adding the sysroot package pinned to 2.17, which is what CentOS 7 uses. As sysroot has a __glibc run_exports/strong constraint, this is added to the build & host environment as well as the final package dependencies

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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.

[conda-forge-webservices[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) and found it was in an excellent condition.

[jakirkham]

Seeing the same issue as PR: https://github.com/conda-forge/openmpi-feedstock/pull/142

[leofang]

@jakirkham since we're rebuilding the package to fix the upload issue, would you like me to move your change there (#142)?

[jakirkham]

Sure if you would like to have it there

Am also ok waiting until the current issues are resolved

[jakirkham]

Done in PR: https://github.com/conda-forge/openmpi-feedstock/pull/142

[leofang]

Thanks for help John! 🙏 Yes I rebased your commit against #142.

[jakirkham]

Thanks Leo! 🙏