Can't use dots

Signed-off-by: Pete Wall <pete.wall@grafana.com>

Author: petewall

charts/k8s-monitoring/docs/examples/features/profiling/default/alloy-profiles.alloy

@@ -47,7 +47,7 @@ pyroscope.write {{ include "helper.alloy_name" .name | quote }} {
 
   external_labels = {
     cluster = {{ $.Values.cluster.name | quote }},
-    k8s.cluster.name = {{ $.Values.cluster.name | quote }},
+    k8s_cluster_name = {{ $.Values.cluster.name | quote }},
   }
 }
 {{- end }}