Remove reference to deprecated openmp package. Use llvm-openmp instead.

[arthurp]

Checklist

• [x] Used a personal fork of the feedstock to propose changes
• [x] Bumped the build number (if the version is unchanged)
• [x] 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.

The openmp package appears to be deprecated and has not been updated since version 8. Other packages have switched to llvm-openmp, so do the same. This allows us to build against LLVM 12.

Also this avoids confusing conflicts caused by the fact that this package effectively required LLVM 8, but other packages require recent LLVM versions. The result was that if graphblas was installed many packages would be forced to very old versions.

[conda-forge-linter]

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.

[arthurp]

@conda-forge-admin, please rerender

[github-actions[bot]]

Hi! This is the friendly automated conda-forge-webservice. I tried to rerender for you, but it looks like I wasn't able to push to the master branch of KatanaGraph/graphblas-feedstock. Did you check the "Allow edits from maintainers" box?

NOTE: PRs from organization accounts cannot be rerendered because of GitHub permissions.

[eriknw]

LGTM, thanks @arthurp !