Migrate Gitcoin to `code_metrics_by_project_v1`

[ccerv1]

What is it?

Once we complete the model refactoring, we should assist Gitcoin to migrate to the new schema. See here for the relevant portions of their code base: https://github.com/gitcoinco/grants-stack/pull/3344

We should time this for after GG20 (Tuesday May 7)