new build: fix openmp issue

[xoviat]

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-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.

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

For recipe:

• License is not an SPDX identifier (or a custom LicenseRef) nor an SPDX license expression.

Documentation on acceptable licenses can be found here.

[xoviat]

this build should resolve this issue: https://ci.appveyor.com/project/xianyi/openblas/builds/37531215/job/8bsnwgmaw3ahnjgh#L116887

note: this is not a regression from flang 5.0.0, because OpenMP was not working on 5.0.0.

[xoviat]

fix confirmed.

[xoviat]

@conda-forge-admin rerender

[xoviat]

cc @isuruf