feat: bump to 4.2.0 (#229)

Author: maxday

RELEASE.CHANGELOG.md

@@ -1,3 +1,7 @@
+### October 7, 2026
+`4.2.0`
+- Add a `w3c()` helper to `LambdaContext` that returns the W3C trace-context fields (`traceparent`, `tracestate`, `baggage`) carried on `clientContext.w3c` at invoke time ([#228](https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/228))
+
 ### September 24, 2026
 `4.1.0`
 - Add pre-fork hooks for multi-concurrent (Lambda Managed Instances) mode. A function can register callables with the `@register_pre_fork` decorator from `awslambdaric.lambda_concurrency_hooks`; they run once in the parent process, after the handler is imported and before worker processes are started. Workers re-import the handler in their own process, so hooks are for external side effects (starting a subprocess, warming a local service, writing to `/tmp`) and share no in-memory state with workers. A hook that raises is reported to the Runtime API as an INIT error with the type `Runtime.PreForkError` and no worker is started. No impact on the standard on-demand path.

awslambdaric/__init__.py

@@ -2,4 +2,4 @@
 Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 """
 
-__version__ = "4.1.0"
+__version__ = "4.2.0"