Remove span_name as high cardinality label from tempo remote write to Prometheus

Author: mrnicegyu11

services/monitoring/tempo_config.yaml.j2

@@ -21,6 +21,12 @@ compactor:
 # and via https://github.com/ITISFoundation/osparc-ops-environments/issues/1086
 metrics_generator:
   processor:
+    span_metrics:
+      dimensions:
+        - service
+        - span_kind
+        - status_code
+        # Intentionally exclude span_name to prevent high cardinality
     local_blocks:
       filter_server_spans: false
       flush_to_storage: true