Reapply "mimirpb: Clone metadata fields rather than maintaining references (#13573)"

This reverts commit 69ca33a.

Author: tcard

CHANGELOG.md

@@ -519,6 +519,7 @@
 * [BUGFIX] Block-builder-scheduler: Fix bugs in handling of partitions with no commit. #12130
 * [BUGFIX] Ingester: Fix issue where ingesters can exit read-only mode during idle compactions, resulting in write errors. #12128
 * [BUGFIX] otlp: Reverts #11889 which has a pooled memory re-use bug. #12266
+* [BUGFIX] Ingester: Fix issue where metadata stored in ingesters indirectly prevents large Kafka record buffers from being garbage collected, resulting in unusual memory growth. #13573
 
 ### Mixin
 

pkg/mimirpb/mimir.pb.go

@@ -1,5 +1,5 @@
 diff --git a/pkg/mimirpb/mimir.pb.go b/pkg/mimirpb/mimir.pb.go
-index e7d3c6a439..dda8609298 100644
+index 3a886f5049..dda8609298 100644
 --- a/pkg/mimirpb/mimir.pb.go
 +++ b/pkg/mimirpb/mimir.pb.go
 @@ -14,7 +14,6 @@ import (
@@ -526,9 +526,9 @@ index e7d3c6a439..dda8609298 100644
 -	}
 -	if len(unit) > 0 || len(help) > 0 || metricType != 0 {
 -		metadata.add(normalizedMetricName, MetricMetadata{
--			MetricFamilyName: normalizedMetricName,
--			Help:             help,
--			Unit:             unit,
+-			MetricFamilyName: strings.Clone(normalizedMetricName),
+-			Help:             strings.Clone(help),
+-			Unit:             strings.Clone(unit),
 -			Type:             MetricMetadata_MetricType(metricType),
 -		})
 -	}