fix: convert third-party image URLs from artifactapi proxies to upstream registries

- valkey: docker.io/valkey/valkey (was artifactapi/dockerhub)
- redis_exporter: docker.io/oliver006/redis_exporter (was artifactapi/dockerhub)

Kept docker-internal images unchanged per policy.

apps/base/cheeztv/valkey.yaml

@@ -24,7 +24,7 @@ metadata:
 spec:
   shards: 1
   replicas: 2
-  image: artifactapi.k8s.syd1.au.unkin.net/dockerhub/valkey/valkey:9.0.0
+  image: docker.io/valkey/valkey:9.0.0
   # redis_exporter sidecar (:9121, port name `metrics`) on every ValkeyNode pod;
   # the operator manages a dedicated _exporter ACL user for it. Image overridden
   # from the operator default (bare dockerhub oliver006/redis_exporter:v1.80.0)
@@ -32,7 +32,7 @@ spec:
   # in vmpodscrape.yaml alongside this file.
   exporter:
     enabled: true
-    image: artifactapi.k8s.syd1.au.unkin.net/dockerhub/oliver006/redis_exporter:v1.89.0
+    image: docker.io/oliver006/redis_exporter:v1.89.0
   scheduling:
     node:
       spread: