Deprecate passing a worker to PipelineRunner.run()

Register the worker with PipelineRunner.add_workers() before calling
run() instead. The worker argument still works but now emits a
DeprecationWarning and will be removed in a future release.

Update the runner docstrings, the run_test() helper, and all examples
(including the asyncio.gather() forms) to use the new pattern.

examples/getting-started/01a-local-audio.py

@@ -44,7 +44,8 @@ async def main():
 
     runner = PipelineRunner(handle_sigint=False if sys.platform == "win32" else True)
 
-    await asyncio.gather(runner.run(worker), say_something())
+    await runner.add_workers(worker)
+    await asyncio.gather(runner.run(), say_something())
 
 
 if __name__ == "__main__":