Flask3 example doesn't work with additional dependencies

I've tried to run the example with an additional dependency PyGithub but it fails to run using vercel dev:

> Built @vercel/python@latest:api/index.py [6s]
ModuleNotFoundError: No module named '_cffi_backend'
thread '<unnamed>' panicked at /Users/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/pyo3-0.20.2/src/err/mod.rs:788:5:
Python API call failed
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Traceback (most recent call last):
  File "/Users/okonet/Library/Caches/com.vercel.fun/runtimes/python3/../python/bootstrap.py", line 147, in <module>
    lambda_runtime_main()
  File "/Users/okonet/Library/Caches/com.vercel.fun/runtimes/python3/../python/bootstrap.py", line 127, in lambda_runtime_main
    fn = lambda_runtime_get_handler()
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/okonet/Library/Caches/com.vercel.fun/runtimes/python3/../python/bootstrap.py", line 113, in lambda_runtime_get_handler
    mod = importlib.import_module(module_name)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.11/3.11.2_1/Frameworks/Python.framework/Versions/3.11/lib/python3.11/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1206, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1178, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1149, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 940, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/vc__handler__python.py", line 13, in <module>
    __vc_spec.loader.exec_module(__vc_module)
  File "<frozen importlib._bootstrap_external>", line 940, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/private/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/./api/index.py", line 2, in <module>
    from github import Github
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/github/__init__.py", line 51, in <module>
    from . import Auth
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/github/Auth.py", line 33, in <module>
    import jwt
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/jwt/__init__.py", line 1, in <module>
    from .api_jwk import PyJWK, PyJWKSet
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/jwt/api_jwk.py", line 7, in <module>
    from .algorithms import get_default_algorithms, has_crypto, requires_cryptography
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/jwt/algorithms.py", line 12, in <module>
    from .utils import (
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/jwt/utils.py", line 7, in <module>
    from cryptography.hazmat.primitives.asymmetric.ec import EllipticCurve
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/cryptography/hazmat/primitives/asymmetric/ec.py", line 11, in <module>
    from cryptography.hazmat._oid import ObjectIdentifier
  File "/var/folders/8z/jnh1lm1j6_vbhbc66cyrp3zw0000gn/T/zeit-fun-00bcf47e5b271/cryptography/hazmat/_oid.py", line 7, in <module>
    from cryptography.hazmat.bindings._rust import (
pyo3_runtime.PanicException: Python API call failed
LambdaError: RequestId: 7bc5e915-4323-4dbe-8726-59ec09ba52ea Process exited before completing request
    at Lambda.<anonymous> (/Users/okonet/.fnm/node-versions/v18.18.2/installation/lib/node_modules/vercel/node_modules/@vercel/fun/dist/src/index.js:110:27)
    at Generator.next (<anonymous>)
    at fulfilled (/Users/okonet/.fnm/node-versions/v18.18.2/installation/lib/node_modules/vercel/node_modules/@vercel/fun/dist/src/index.js:24:58)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

To reproduce, use this path:

diff --git a/python/flask3/api/index.py b/python/flask3/api/index.py
index 20726e5e..d3bfc045 100644
--- a/python/flask3/api/index.py
+++ b/python/flask3/api/index.py
@@ -1,4 +1,5 @@
 from flask import Flask
+from github import Github
 
 app = Flask(__name__)
 
@@ -8,4 +9,4 @@ def home():
 
 @app.route('/about')
 def about():
-    return 'About'
\ No newline at end of file
+    return 'About'
diff --git a/python/flask3/requirements.txt b/python/flask3/requirements.txt
index 047e9501..396a6068 100644
--- a/python/flask3/requirements.txt
+++ b/python/flask3/requirements.txt
@@ -1 +1,2 @@
 Flask==3.0.0
+PyGithub==2.2.0

Start with python/flask3/api/index.py and python/flask3/requirements.txt, then reproduce the reported import failure with vercel dev after adding PyGithub==2.2.0. Trace the dependency-loading behavior shown in the error and verify that the Flask 3 example runs successfully with PyGithub installed.