Remove grafana, metricspi groups

With the Metrics Pi decommissioned and Victoria Metrics and Grafana
running in Kubernetes now, these groups are no longer needed.

hosts

@@ -1,18 +1,12 @@
 [all:vars]
 ansible_python_interpreter=/usr/bin/python3
 
-[alertmanager:children]
-metricspi
-
 [aria2]
 file0.pyrocufflink.blue
 
 [bitwarden_rs]
 bw0.pyrocufflink.blue
 
-[blackbox-exporter:children]
-metricspi
-
 [burp-client]
 bw0.pyrocufflink.blue
 cloud0.pyrocufflink.blue
@@ -58,8 +52,6 @@ file0.pyrocufflink.blue
 [gitea]
 git0.pyrocufflink.blue
 
-[grafana]
-
 [graylog]
 
 [hassdb]
@@ -87,8 +79,6 @@ k8s-amd64-n2.pyrocufflink.blue
 k8s-controller
 k8s-node
 
-[metricspi]
-
 [minio:children]
 burp-server
 
@@ -167,17 +157,6 @@ matrix0.pyrocufflink.blue
 [unifi]
 unifi1.pyrocufflink.blue
 
-[victoria-metrics]
-
-[victoria-metrics:children]
-metricspi
-
-[vmagent:children]
-victoria-metrics
-
-[vmalert:children]
-metricspi
-
 [vm-hosts]
 
 [wheelhost]