Review secrets for data-platform apps

[Ardiea]

A lot of the dataplatform apps (Airbyte, Dagster, Redash) have their secrets manually populated in vault. That makes it hard to recreate environments (requires tribal knowledge / code review). We should take as many of these secrets as we can and put them into sops and then have the pulumi code populate them into vault.

Should figure out how to import the existing values into the pulumi state so we don't break anything, if possible. Otherwise we can probably get away with backing up the existing config, blowing it away, and then recreating with pulumi.