chore: update changelog to reflect #3098 fixed #2791 (#3111)

Author: dyladan

experimental/CHANGELOG.md

@@ -26,6 +26,8 @@ All notable changes to experimental packages in this project will be documented
 * fix(histogram): fix maximum when only values < -1 are provided [#3086](https://github.com/open-telemetry/opentelemetry-js/pull/3086) @pichlermarc
 * fix(sdk-metrics-base): fix PeriodicExportingMetricReader keeping Node.js process from exiting
   [#3106](https://github.com/open-telemetry/opentelemetry-js/pull/3106) @seemk
+* fix(otlp-proto): fixes [#2791](https://github.com/open-telemetry/opentelemetry-js/issues/2791) otlp proto exporters no longer share a single global proto definition
+  [#3098](https://github.com/open-telemetry/opentelemetry-js/pull/3098) @legendecas
 
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