Add release notes for Go Feature Management v2.3.1

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Co-authored-by: linglingye001 <143174321+linglingye001@users.noreply.github.com>

Author: Copilot

releaseNotes/GoFeatureManagement.md

@@ -2,6 +2,12 @@
 
 [Source code][source_code] | [Package][package] | [Samples][samples]
 
+## v2.3.1 - April 15, 2026
+
+### Bug Fixes
+
+* Fixed a bug where `isEnabled` returned `false` when an unregistered feature filter was encountered while using `RequirementType` `Any`, even if other registered filters in the list could enable the feature. [#158](https://github.com/microsoft/FeatureManagement-JavaScript/pull/158)
+
 ## v1.1.1 - October 17, 2025
 
 ### Enhancement