support newer python versions (#11675)

When we added the option of getting `al2023` in addition to `al2`, this required a python version bump for those apps on `al2023`. Python 3.10 had a breaking minor change. #11541 mostly fixed it, with some comments.

OP hasn't replied to feedback on that PR, so I've take it over from them.

.changeset/angry-moles-cross.md

@@ -0,0 +1,5 @@
+---
+"@vercel/python": minor
+---
+
+support newer python versions

packages/python/vc_init.py

@@ -13,6 +13,7 @@
 __vc_spec.loader.exec_module(__vc_module)
 __vc_variables = dir(__vc_module)
 
+_use_legacy_asyncio = sys.version_info < (3, 10)
 
 def format_headers(headers, decode=False):
     keyToList = {}
@@ -198,16 +199,25 @@ def __call__(self, app, body):
                 ASGI instance using the connection scope.
                 Runs until the response is completely read from the application.
                 """
-                loop = asyncio.new_event_loop()
-                self.app_queue = asyncio.Queue(loop=loop)
+                if _use_legacy_asyncio:
+                    loop = asyncio.new_event_loop()
+                    self.app_queue = asyncio.Queue(loop=loop)
+                else:
+                    self.app_queue = asyncio.Queue()
                 self.put_message({'type': 'http.request', 'body': body, 'more_body': False})
 
                 asgi_instance = app(self.scope, self.receive, self.send)
 
-                asgi_task = loop.create_task(asgi_instance)
-                loop.run_until_complete(asgi_task)
+                if _use_legacy_asyncio:
+                    asgi_task = loop.create_task(asgi_instance)
+                    loop.run_until_complete(asgi_task)
+                else:
+                    asyncio.run(self.run_asgi_instance(asgi_instance))
                 return self.response
 
+            async def run_asgi_instance(self, asgi_instance):
+                await asgi_instance
+
             def put_message(self, message):
                 self.app_queue.put_nowait(message)