OpenID Connect authentication for external feeds

Octopus has introduced OpenID Connect (OIDC) authentication for its external feeds, allowing OAuth 2.0 to be used to access container feeds without managing or rotating credentials manually. This update supports AWS Elastic Container Registry (ECR), Azure Container Registry (ACR), and Google Container Registry (GCR), providing improved security and simplifying credential management by generating short-lived credentials during deployment. For AWS ECR, users can set up an IAM role with a trust policy, while Azure ACR requires app registration with federated credentials, and Google GCR uses Workload Identity Federation. This feature, available for Cloud customers and soon for self-hosted customers, enhances security by ensuring tokens are valid only for specific feeds and spaces, aligning with modern cloud practices for secure, token-based authentication in deployment pipelines.