operator: Remove mutations to non-updatable statefulset fields (#8875)

operator/CHANGELOG.md

@@ -1,5 +1,6 @@
 ## Main
 
+- [8875](https://github.com/grafana/loki/pull/8875) **Red-GV**: Remove mutations to non-updatable statefulset fields
 - [7451](https://github.com/grafana/loki/pull/7451) **btaani**: Add support for rules configmap sharding
 - [8672](https://github.com/grafana/loki/pull/8672) **periklis**: Add support for memberlist bind network configuration
 - [8748](https://github.com/grafana/loki/pull/8748) **periklis**: Add alertingrule tenant id label for all rules

operator/internal/manifests/mutate.go

@@ -234,13 +234,7 @@ func mutateStatefulSet(existing, desired *appsv1.StatefulSet) error {
 	if existing.CreationTimestamp.IsZero() {
 		existing.Spec.Selector = desired.Spec.Selector
 	}
-	existing.Spec.PodManagementPolicy = desired.Spec.PodManagementPolicy
 	existing.Spec.Replicas = desired.Spec.Replicas
-	for i := range existing.Spec.VolumeClaimTemplates {
-		existing.Spec.VolumeClaimTemplates[i].TypeMeta = desired.Spec.VolumeClaimTemplates[i].TypeMeta
-		existing.Spec.VolumeClaimTemplates[i].ObjectMeta = desired.Spec.VolumeClaimTemplates[i].ObjectMeta
-		existing.Spec.VolumeClaimTemplates[i].Spec = desired.Spec.VolumeClaimTemplates[i].Spec
-	}
 	if err := mergeWithOverride(&existing.Spec.Template, desired.Spec.Template); err != nil {
 		return err
 	}