to deprecation schedule, add identity map v2

Author: genwhittTTD

docs/ref-info/deprecation-schedule.md

@@ -79,3 +79,9 @@ The latest ZIP file is linked in the Release Notes column in the following table
 | ------- | ------ | ------ | ------ | ------ |
 | Q2 2025 | xxx | xxx | xxx | xxx | -->
 <!-- | Q1 2025 | 5.49.7 | [v5.49.7](https://github.com/IABTechLab/uid2-operator/releases/tag/v5.49.7) | Mar 19, 2025 | Mar 31, 2026 | -->
+
+## POST /identity/map Endpoint v2
+
+[Version 2 of the POST /identity/map endpoint](../endpoints/post-identity-map-v2.md) has been superseded by version 3, which includes the additional advantages listed in [Version 3 Improvements](../endpoints/post-identity-map.md#version-3-improvements).
+
+Version 2 of this endpoint will be deprecated on June 30, 2026. After that date, it will no longer be supported.