(#975) Hardening Redis server authn

[arielr-lt]

Adds the Redis hardening changes across every environment: each redis-configmap.yaml now includes a secret-sourced requirepass snippet, the StatefulSet mounts a redis-auth Secret to pass --requirepass to redis-server and authenticate its probes, and the environment’s external-secrets-operator.yaml defines the redis-auth ExternalSecret that pulls redis-password from the existing AWS Secrets Manager entry.

Contributes to: #975

[rohit-joy]

@arielr-lt Is this Redis StatefulSet for Registry or for Argo?

[arielr-lt]

@rohit-joy this is for the Registry, Argo does not use Redis

[rohit-joy]

@arielr-lt Can you please separate the PRs? Please don't mix Argo files with Redis changes.

[arielr-lt]

@arielr-lt Can you please separate the PRs? Please don't mix Argo files with Redis changes.

oh gosh! I made by mistake, not meant to do it like that, I will fix it