Bump arrstack app images to -unkin3

Deploy the merged active-active work (process lifecycle, Redis rate
limiter, radarr MediaCover->S3) now on each fork's main; the cluster
still runs -unkin2 so the merged code is undeployed.

- sonarr: v5.0.0-unkin2 -> v5.0.0-unkin3
- radarr: v6.4.2-unkin2 -> v6.4.2-unkin3
- prowlarr: v2.6.2-unkin2 -> v2.6.2-unkin3

apps/base/arrstack/prowlarr/deployment.yaml

@@ -64,7 +64,7 @@ spec:
               memory: 64Mi
       containers:
         - name: prowlarr
-          image: artifactapi.k8s.syd1.au.unkin.net/docker-internal/prowlarr:v2.6.2-unkin2
+          image: artifactapi.k8s.syd1.au.unkin.net/docker-internal/prowlarr:v2.6.2-unkin3
           imagePullPolicy: IfNotPresent
           command:
             - /app/Prowlarr

apps/base/arrstack/radarr/deployment.yaml

@@ -64,7 +64,7 @@ spec:
               memory: 64Mi
       containers:
         - name: radarr
-          image: artifactapi.k8s.syd1.au.unkin.net/docker-internal/radarr:v6.4.2-unkin2
+          image: artifactapi.k8s.syd1.au.unkin.net/docker-internal/radarr:v6.4.2-unkin3
           imagePullPolicy: IfNotPresent
           command:
             - /app/Radarr

apps/base/arrstack/sonarr/deployment.yaml

@@ -64,7 +64,7 @@ spec:
               memory: 64Mi
       containers:
         - name: sonarr
-          image: artifactapi.k8s.syd1.au.unkin.net/docker-internal/sonarr:v5.0.0-unkin2
+          image: artifactapi.k8s.syd1.au.unkin.net/docker-internal/sonarr:v5.0.0-unkin3
           imagePullPolicy: IfNotPresent
           command:
             - /app/Sonarr