fix: update Helm chart pythonpath to Python 3.13

The chart default PYTHONPATH still pointed to python3.12
site-packages. Deployments using --reuse-values kept the
old value, causing cli-job hooks to fail with
ModuleNotFoundError.

OBS-1999

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: aarthy-dk

deploy/charts/observability-app/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 name: dataops-observability-app
 type: application
 appVersion: "2"
-version: "3.0.1"
+version: "3.0.2"
 
 description: DataOps Observability
 home: https://datakitchen.io

deploy/charts/observability-app/values.yaml

@@ -10,7 +10,7 @@ observability:
   cors_domains: "localhost:*"
   services_secrets_name: external-service-keys
   keys_secrets_name: internal-keys
-  pythonpath: /dk/lib/python3.12/site-packages
+  pythonpath: /dk/lib/python3.13/site-packages
   image:
     repository: docker.io/datakitchen
     tag: "v2"