Add Changelog entry for emscripten-core#26582

Author: dschuff

ChangeLog.md

@@ -27,6 +27,8 @@ See docs/process.md for more on how version tagging works.
   `--experimental-wasm-bulk-memory` flags when used with versions of node older
   than v16. (#26560)
 - SDL3 port updated from 3.2.30 to 3.4.2 (#26572)
+- Fixed a race condition in syscall proxying that caused some hangs and ASan
+  errors (#26582)
 
 5.0.4 - 03/23/26
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