Update CHANGELOG

Moved 'Support span envelope item type' feature to internal section.

Author: buenaflor

CHANGELOG.md

@@ -2,15 +2,15 @@
 
 ## Unreleased
 
-### Features
-
-- Support `span` envelope item type ([#4935](https://github.com/getsentry/sentry-java/pull/4935))
-
 ### Improvements
 
 - Avoid forking `rootScopes` for Reactor if current thread has `NoOpScopes` ([#4793](https://github.com/getsentry/sentry-java/pull/4793))
   - This reduces the SDKs overhead by avoiding unnecessary scope forks
 
+### Internal
+
+- Support `span` envelope item type ([#4935](https://github.com/getsentry/sentry-java/pull/4935))
+
 ## 8.27.1
 
 ### Fixes