FIX(promtail): promtail Loki endpoint

- to use loki namespace
- Change Loki URL from loki.logging to loki.loki namespace
- Fixes DNS lookup error and readiness probe failures
- Resolves Healthy <-> Progressing oscillation in ArgoCD

promtail/helm-values.yaml

@@ -5,7 +5,7 @@
 # Loki endpoint
 config:
   clients:
-    - url: http://loki.logging.svc.cluster.local:3100/loki/api/v1/push
+    - url: http://loki.loki.svc.cluster.local:3100/loki/api/v1/push
 
 # Default scrape config (use defaults)
 defaultVolumes: