Update CHANGELOG.md

Author: jamescrosswell

CHANGELOG.md

@@ -11,6 +11,7 @@
 
 - The HTTP instrumentation uses the span created for the outgoing request in the sentry-trace header, fixing the parent-child relationship between client and server ([#4264](https://github.com/getsentry/sentry-dotnet/pull/4264))
 - InvalidOperationException sending attachments on Android with LLVM enabled ([#4276](https://github.com/getsentry/sentry-dotnet/pull/4276))
+- When CaptureFeedback methods are called with invalid email addresses, a warning is now logged if Debug mode is enabled (explaining why the feedback has been dropped) ([#4284](https://github.com/getsentry/sentry-dotnet/pull/4284))
 
 ### Dependencies