OpenTelemetry Collector v0.155.0 removes stabilized feature gates

Category: Infrastructure
Status: confirmed
Sources: Collector v0.155.0 release
Summary: The OpenTelemetry Collector core released v0.155.0 on 2026-06-23. Breaking changes remove several stabilized feature gates (confighttp.framedSnappy, configoptional.AddEnabledField, confmap.newExpandedValueSanitizer, exporter.PersistRequestContext, otelcol.printInitialConfig, telemetry.UseLocalHostAsDefaultMetricsAddress, pdata.enableRefCounting) and rename memory_limiter processor metrics to carry a memory_limiter prefix. The schemagen CLI moved into the core repository, and mdatagen gains versioned-metrics support for migrating to new semantic conventions.
Why it matters: Removing stabilized gates and renaming processor metrics can break collector configs and dashboards that still reference the old names.
Follow-up: Track config and dashboard migration reports from the renamed memory_limiter metrics.