Do not consider prometheus-exporters as part of the prometheus group

This makes us rebuild/restart exporters when running `just install-service prometheus`,
which we don't like.

group_vars/matrix_servers

@@ -340,11 +340,11 @@ devture_systemd_service_manager_services_list_auto: |
     +
     ([{'name': 'matrix-prometheus.service', 'priority': 4000, 'groups': ['matrix', 'monitoring', 'prometheus', 'prometheus-core']}] if matrix_prometheus_enabled else [])
     +
-    ([{'name': (prometheus_node_exporter_identifier + '.service'), 'priority': 3900, 'groups': ['matrix', 'monitoring', 'prometheus', 'prometheus-exporters']}] if prometheus_node_exporter_enabled else [])
+    ([{'name': (prometheus_node_exporter_identifier + '.service'), 'priority': 3900, 'groups': ['matrix', 'monitoring', 'prometheus-exporters', 'prometheus-node-exporter']}] if prometheus_node_exporter_enabled else [])
     +
-    ([{'name': (prometheus_postgres_exporter_identifier + '.service'), 'priority': 3900, 'groups': ['matrix', 'monitoring', 'prometheus', 'prometheus-exporters']}] if prometheus_postgres_exporter_enabled else [])
+    ([{'name': (prometheus_postgres_exporter_identifier + '.service'), 'priority': 3900, 'groups': ['matrix', 'monitoring', 'prometheus-exporters', 'prometheus-postgres-exporter']}] if prometheus_postgres_exporter_enabled else [])
     +
-    ([{'name': 'matrix-prometheus-nginxlog-exporter.service', 'priority': 3900, 'groups': ['matrix', 'monitoring', 'prometheus', 'prometheus-exporters']}] if matrix_prometheus_nginxlog_exporter_enabled else [])
+    ([{'name': 'matrix-prometheus-nginxlog-exporter.service', 'priority': 3900, 'groups': ['matrix', 'monitoring', 'prometheus-exporters', 'prometheus-nginxlog-exporter']}] if matrix_prometheus_nginxlog_exporter_enabled else [])
     +
     ([{'name': (redis_identifier + '.service'), 'priority': 750, 'groups': ['matrix', 'redis']}] if redis_enabled else [])
     +