[helm chart] secrets keys should be set in a secret, not as clear text env in deployment

[draeron]

All secret keys (for aws, minio etc) should be in a external k8s secret instead of directly be as env variable.

https://github.com/gomods/athens/blob/main/charts/athens-proxy/templates/deployment.yaml#L103

[arschles]

@draeron are you wanting to create a secret outside of the helm chart, and then bring it into your pod as an environment variable?

[draeron]

By external i meant the chart itself should create the secrets and the deployment should refer to it via a secretKeyRef.