Add Holmes sentryDSN to parent chart values (#2026)

The HolmesGPT subchart no longer ships a default sentryDSN value.
Explicitly pass the Sentry DSN so SaaS deployments continue sending
telemetry while standalone Holmes installs remain DSN-free.

https://claude.ai/code/session_01PSuf8dvymACh6KhYkjWN18

Co-authored-by: Claude <noreply@anthropic.com>

Author: aantn

helm/robusta/values.yaml

@@ -23,6 +23,9 @@ automountServiceAccountToken: true
 
 enableHolmesGPT: false
 
+holmes:
+  sentryDSN: "https://aa95c183188a6ddf134ebfffe85fd108@o4510692373299200.ingest.de.sentry.io/4510707946094672"
+
 # see https://docs.robusta.dev/master/user-guide/configuration.html#global-config and https://docs.robusta.dev/master/configuration/additional-settings.html#global-config
 globalConfig:
   check_prometheus_flags: true