[docs] Add PR authors to change log

Author: nhairs

docs/changelog.md

@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `pythonjsonlogger.[ORJSON,MSGSPEC]_AVAILABLE` no longer imports the respective package when determining availability.
 - `pythonjsonlogger.[orjson,msgspec]` now throws a `pythonjsonlogger.exception.MissingPackageError` when required libraries are not available. These contain more information about what is missing whilst still being an `ImportError`.
 - `defaults` parameter is no longer ignored and now conforms to the standard library. Setting a defaults dictionary will add the specified keys if the those keys do not exist in a record or weren't passed by the `extra` parameter when logging a message.
+- `typing_extensions` is only installed on Python version < 3.10.
+
+Thanks @cjwatson and @bharel
 
 ## [3.1.0](https://github.com/nhairs/python-json-logger/compare/v3.0.1...v3.1.0) - 2023-05-28