gh-contrib-update is a CLI utility that will trigger GitHub Contributor calculation updates. It runs against an entire org and forces the backend job on GitHub.com to recalculate all contributions to repositories.
You can run the CLI by downloading the binaries from the releases page and executing it like this:
GITHUB_PAT=<your GitHub PAT> GITHUB_ORG=<the org to update> <path to binary>/gh-contrib-update
Note: If updating all repos is too time intensive, we could update this to read in a migration archive and only update the repos mentioned in the migration archive.