feat: add pod identity association support for EKS addons @litanyofmadness (#256)
## what- Added pod_identity_association parameter to EKS addons configuration
- Maps service account names to IAM role ARNs for pod identity authentication
- Maintains backward compatibility with existing configurations
why
- Enables modern IAM authentication for EKS addons using pod identities
- Aligns with AWS best practices for EKS