Describe the bug
Certain configuration fields in the Loki config are no longer valid in the current version, but still appear in some loki-local-config file

The fields include:

• metric_aggregation_enabled under limits_config
• metric_aggregation under pattern_ingester
• enable_multi_variant_queries under querier.engine

To Reproduce
Steps to reproduce the behavior:

1. Started Loki with the following config:

limits_config:
  metric_aggregation_enabled: true

pattern_ingester:
  enabled: true
  metric_aggregation:
    loki_address: loki:3100

querier:
  engine:
    enable_multi_variant_queries: true

2. Run docker run grafana/loki:latest -config.file=/etc/loki/local-config.yaml
3. Error occurs:

Expected behavior
Ignore deprecated fields with a warning
OR explicitly remove them from all documentation and example config files

Environment:

• Infrastructure: laptop, macos
• Deployment tool: docker compose

Screenshots, Promtail config, or terminal output

failed parsing config: /etc/loki/local-config.yaml: yaml: unmarshal errors:
  line 29: field metric_aggregation_enabled not found in type validation.plain
  line 43: field metric_aggregation not found in type pattern.Config
  line 54: field enable_multi_variant_queries not found in type logql.EngineOpts.