[OTLP Endpoint] Add deployment.environment.name to the list of promoted resource attributes

[cyrille-leclerc]

Is your feature request related to a problem? Please describe.

OpenTelemetry semantic convention renamed the deployment.environment resource attribute into deployment.environment.name (here) and the Loki OTLP endpoint is only promoting deployment.environment as logstream label, creating a feature gap for users embracing the new attribute name.

Describe the solution you'd like

The Loki OTLP endpoint could by default promote as logstream label the new resource attribute deployment.environment.name in addition to the already promoted deployment.environment to help users migrate.

Note that we probably don't want to do renaming during the ingestion and help users migrating to just one name as such a schema normalization capability is not in place in any of Loki, Mimir, Tempo, or Pyroscope components today.

Describe alternatives you've considered

Don't change the default behaviour, let users encounter regressions as they adopt the new resource attribute name and figure out themselves the solution: edit the Loki config file for self managed users and open a support ticket for Grafana Cloud users.

Additional context
Add any other context or screenshots about the feature request here.

cc @sandeepsukhani and @vlad-diachenko for Loki, cc @aknuds1 and @jesusvazquez who are rolling out a similar resource attribute promotion feature in for Prometheus & Mimir.

[jesusvazquez]

I've made sure to record this as well in our design doc to do this in Mimir https://docs.google.com/document/d/1tVeuVvt4A_Y9bDUqivngnmFnXSA06ge9wONbvfMz5PQ/edit?tab=t.0 thanks @cyrille-leclerc