Changes to Azure Artifacts Upstream Behavior

Introduced a new security behavior for Azure Artifacts feeds that limits access to externally sourced packages when internally sourced packages are already present. This prevents the consumption of malicious packages from public registries. The behavior is applied when an internally sourced version exists or when consuming a package for the first time if an upstream version is internally sourced. Versions from public registries will be blocked unless explicitly allowed via configuration. An organization-wide security policy 'Additional protections when using public package registries' can be toggled off to opt out.