Use internal proxies for Helm charts and PyPI packages

- Switch Helm chart dependencies to OCI-based internal registry
  (deps.global.bsf.tools/registry-1.docker.io-helmoci/bitnamicharts)
- Remove public helm repo adds (not needed for OCI)
- Add PIP_INDEX_URL to use internal PyPI proxy for all pip installs

This reduces dependencies on public internet during CI builds.

helm/orchard/Chart.yaml

@@ -17,13 +17,13 @@ maintainers:
 dependencies:
   - name: postgresql
     version: "15.5.x"
-    repository: https://charts.bitnami.com/bitnami
+    repository: oci://deps.global.bsf.tools/registry-1.docker.io-helmoci/bitnamicharts
     condition: postgresql.enabled
   - name: minio
     version: "14.x.x"
-    repository: https://charts.bitnami.com/bitnami
+    repository: oci://deps.global.bsf.tools/registry-1.docker.io-helmoci/bitnamicharts
     condition: minio.enabled
   - name: redis
     version: "19.x.x"
-    repository: https://charts.bitnami.com/bitnami
+    repository: oci://deps.global.bsf.tools/registry-1.docker.io-helmoci/bitnamicharts
     condition: redis.enabled