Helm chart failing to create workers with the new release.

[jacobtomlinson]

Actually @jacobtomlinson it's still failing to create workers with the new release.

I believe because here the env variable must be a string. So need to cast these

Originally posted by @dyu-bot in #766 (comment)

[jacobtomlinson]

Moved this to an issue.

I think we probably want to update the helm chart template so that if the values are set to nil we just don't set the environment variables.

cc @Matt711