Add resources to migrate-db container

[AlissonRS]

When using ArgoCD for deploying Flagsmith, it thinks the cluster is not synced with the chart because it finds a diff, as the migrate-db container doesn't include a resources: {}.

I understand for a migration job which is short lived adding resources may not be relevant enough, but this helps avoiding sync issues with GitOps tools, and may also avoid issues with clusters that require all workloads to have resources defined.

This affects t he deployment-api.yaml (specifically the migrate-db init container) and the jobs-migrate-db.yaml.

[rolodato]

We don't use ArgoCD in production but this sounds reasonable. We'd be happy to accept a pull request for this!