Add license info to repo_metrics

[ccerv1]

Describe the feature you'd like to request

We need to extract current license information for all repos linked to projects in staging and expose them in our int_repo_metrics_by_project model.

Specifically, we need the field spdxId. See here for an ad hoc fetcher I've used in the past.

Describe the solution you'd like

Option 1: we grab the current license info alongside other current repo stats like stars, forks, etc

Option 2: we create a timestamped history of license changes for all repos we care about (ie, we write the status daily or monthly)

Describe alternatives you've considered

Continue to do this ad hoc using a script, just for repos we care about

[ccerv1]

@ravenac95 all of the licenses are coming back null ...

SELECT 
  name_with_owner,
  license_name,
  license_spdx_id
FROM `oso.repositories_ossd`
where license_name is not null

[ccerv1]

Also tagging the dbt model implementations #1433