Update Chart version to 6.6.0

Author: braintrust-bot[bot]

braintrust/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v2
 name: braintrust
-version: 6.5.0
+version: 6.6.0
 description: A Helm chart to run the Braintrust services for the self-hosted data plane
 type: application
 home: https://github.com/braintrustdata/helm