fix: remove static volumeNames for GCP migration, fix redis image tag

Dynamic PVC provisioning needed on new GCP instance.
Redis image 7.4.3-debian-12-r0 was removed from Docker Hub;
use floating 7.4-debian-12 tag instead.

servers/legion/k8s/adguard/pvc.yaml

@@ -6,7 +6,6 @@ metadata:
   namespace: dns
 spec:
   storageClassName: local-path
-  volumeName: pvc-471e439b-2a69-49fc-9704-4dec6df93855
   accessModes:
     - ReadWriteOnce
   resources:
@@ -20,7 +19,6 @@ metadata:
   namespace: dns
 spec:
   storageClassName: local-path
-  volumeName: pvc-8b8c53fb-b16d-4896-8827-042b7bcbe2dd
   accessModes:
     - ReadWriteOnce
   resources: