[Process] Update CHANGELOG

Move to unreleased.

Author: martincostello

src/OpenTelemetry.Instrumentation.Process/CHANGELOG.md

@@ -2,16 +2,16 @@
 
 ## Unreleased
 
+* Add instrumentation scope version and schema URL to metrics.
+  ([#4088](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/4088))
+
 ## 1.15.1-beta.1
 
 Released 2026-Apr-21
 
 * Updated OpenTelemetry core component version(s) to `1.15.3`.
   ([#4166](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/4166))
 
-* Add instrumentation scope version and schema URL to metrics.
-  ([#4088](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/4088))
-
 ## 1.15.0-beta.1
 
 Released 2026-Jan-21