[Py][Bug] Google GenAI plugin models are unusable in the dev server.

[yesudeep]

Ran:

genkit/py/samples/hello-google-genai 
zsh❯ genkit start -- uv run src/hello_google_genai.py

Visited https://localhost:4000 and said "Hey!" to a model.

Got:

RuntimeError('Event loop is closed')
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/packages/genkit-ai/src/genkit/core/action/_action.py", line 186, in async_tracing_wrapper
    output = await afn(input, ctx)
             ^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/plugins/google-genai/src/genkit/plugins/google_genai/models/gemini.py", line 503, in generate
    return await self._generate(request_contents, request_cfg)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/plugins/google-genai/src/genkit/plugins/google_genai/models/gemini.py", line 528, in _generate
    response = await self._client.aio.models.generate_content(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/google/genai/models.py", line 6415, in generate_content
    response = await self._generate_content(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/google/genai/models.py", line 5414, in _generate_content
    response_dict = await self._api_client.async_request(
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/google/genai/_api_client.py", line 689, in async_request
    result = await self._async_request(http_request=http_request, stream=False)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/google/genai/_api_client.py", line 626, in _async_request
    response = await self._async_httpx_client.request(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpx/_client.py", line 1540, in request
    return await self.send(request, auth=auth, follow_redirects=follow_redirects)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpx/_client.py", line 1629, in send
    response = await self._send_handling_auth(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpx/_client.py", line 1657, in _send_handling_auth
    response = await self._send_handling_redirects(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpx/_client.py", line 1694, in _send_handling_redirects
    response = await self._send_single_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpx/_client.py", line 1730, in _send_single_request
    response = await transport.handle_async_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpx/_transports/default.py", line 394, in handle_async_request
    resp = await self._pool.handle_async_request(req)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpcore/_async/connection_pool.py", line 256, in handle_async_request
    raise exc from None
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpcore/_async/connection_pool.py", line 236, in handle_async_request
    response = await connection.handle_async_request(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpcore/_async/connection.py", line 103, in handle_async_request
    return await self._connection.handle_async_request(request)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpcore/_async/http11.py", line 135, in handle_async_request
    await self._response_closed()
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpcore/_async/http11.py", line 250, in _response_closed
    await self.aclose()
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpcore/_async/http11.py", line 258, in aclose
    await self._network_stream.aclose()
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/httpcore/_backends/anyio.py", line 53, in aclose
    await self._stream.aclose()
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/anyio/streams/tls.py", line 216, in aclose
    await self.transport_stream.aclose()
  File "/Users/yesudeep/code/github.com/firebase/genkit/py/.venv/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 1314, in aclose
    self._transport.close()
  File "/Users/yesudeep/.local/share/uv/python/cpython-3.12.8-macos-aarch64-none/lib/python3.12/asyncio/selector_events.py", line 1210, in close
    super().close()
  File "/Users/yesudeep/.local/share/uv/python/cpython-3.12.8-macos-aarch64-none/lib/python3.12/asyncio/selector_events.py", line 875, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "/Users/yesudeep/.local/share/uv/python/cpython-3.12.8-macos-aarch64-none/lib/python3.12/asyncio/base_events.py", line 794, in call_soon
    self._check_closed()
  File "/Users/yesudeep/.local/share/uv/python/cpython-3.12.8-macos-aarch64-none/lib/python3.12/asyncio/base_events.py", line 540, in _check_closed
    raise RuntimeError('Event loop is closed')

Diagnosis:

#2570 appears to be where it appears to start showing up based on git bisect