Add release notes.

Author: ioquatix

releases.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
   - `IO::Event::Profiler` is moved to dedicated gem: [fiber-profiler](https://github.com/socketry/fiber-profiler).
+  - Perform runtime checks for native selectors to ensure they are supported in the current environment. While compile-time checks determine availability, restrictions like seccomp and SELinux may still prevent them from working.
 
 ## v1.9.0