Update changelog after #26523 (#26545)

Author: sbc100

ChangeLog.md

@@ -20,6 +20,9 @@ See docs/process.md for more on how version tagging works.
 
 5.0.5 (in development)
 ----------------------
+- C++ exceptions are now always thrown as CppException objects rather than raw
+  pointers/numbers.  However, the `.message` and `.stack` fields of the thrown
+  object will only be populated if `-sEXCEPTION_STACK_TRACES` is set. (#26523)
 
 5.0.4 - 03/23/26
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