helm-chart: Shouldn't force use of archive pruning mode when start a validator

[sameh-farouk]

Previously this was necessary because of legacy reasons, now this is not required.

Archive mode make sense for public rpc node (to support indexer and explorer utilities). However, for validators it is completely unnecessary.

The obvious downside for using this mode on validators nodes is storage space, when adding no benefits.

Helm chart should be updated accordingly. See deployment.yaml