Release v19.92.1

Fixed

• Releasing a read model composed in code no longer logs a "no subject could be resolved" warning when every subject-scoped ([PII] or secret) value on it is null. The warning still appears when a subject-scoped value is present and no subject can be resolved. (#4940)
• A [NotProjected] member on a read model projected through IProjectionFor<T> no longer registers a second, empty model-bound projection for it, so the extra observer that stayed Disconnected is gone. (#4964)