Kargo's `GetConfig()` and `RefreshResource()` API endpoints allow unauthenticated access

Kargo manages and automates the promotion of software artifacts. Prior to versions 1.8.7, 1.7.7, and 1.6.3, a bug was found with authentication checks on the `GetConfig()` API endpoint. This allowed unauthenticated users to access this endpoint by specifying an `Authorization` header with any non-empty `Bearer` token value, regardless of validity. This vulnerability did allow for exfiltration of configuration data such as endpoints for connected Argo CD clusters. This data could allow an attacker to enumerate cluster URLs and namespaces for use in subsequent attacks. Additionally, the same bug affected the `RefreshResource` endpoint. This endpoint does not lead to any information disclosure, but could be used by an unauthenticated attacker to perform a denial-of-service style attack against the Kargo API. `RefreshResource` sets an annotation on specific Kubernetes resources to trigger reconciliations. If run on a constant loop, this could also slow down legitimate requests to the Kubernetes API server. This problem has been patched in Kargo versiosn 1.8.7, 1.7.7, and 1.6.3. There are no workarounds for this issue.