feat: Update to support python 3.12

- add case statement to use the asyncio.Queue.shutdown method for 3.13+
- add special handling to allow for similar semantics as
  asyncio.Queue.shutdown for 3.12

Tested on multiple samples in the a2a repo and some examples in this
repo

Author: pstephengoogle

pyproject.toml

@@ -22,10 +22,14 @@ classifiers = [
   "Intended Audience :: Developers",
   "Programming Language :: Python",
   "Programming Language :: Python :: 3",
+<<<<<<< HEAD
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
   "Programming Language :: Python :: 3.13",
+=======
+  "Programming Language :: Python :: 3.12",
+>>>>>>> 8ec734c (feat: Update to support python 3.12)
   "Operating System :: OS Independent",
   "Topic :: Software Development :: Libraries :: Python Modules",
   "License :: OSI Approved :: Apache Software License",

src/a2a/server/events/event_consumer.py

@@ -15,6 +15,12 @@
 from a2a.utils.errors import ServerError
 from a2a.utils.telemetry import SpanKind, trace_class
 
+# This is an alias to the execption for closed queue
+QueueClosed = asyncio.QueueEmpty
+
+# When using python 3.13 or higher, the closed queue signal is QueueShutdown
+if sys.version_info >= (3, 13):
+    QueueClosed = asyncio.QueueShutDown
 
 # This is an alias to the exception for closed queue
 QueueClosed = asyncio.QueueEmpty