The Loki package is derived from the Grafana Loki project's logproto and
promtail packages with removals to support Grafana's needs.

- https://github.com/grafana/loki/tree/2fc20af9a4e55483afe0f09f8a8119ab380daea9/clients/pkg/promtail/client
- https://github.com/grafana/loki/tree/2fc20af9a4e55483afe0f09f8a8119ab380daea9/pkg/logproto