test(nox): disable multidict extensions on 3.13 for now

noxfile.py

@@ -1,5 +1,7 @@
 """nox config for pytekukko."""
 
+from typing import cast
+
 import nox
 
 nox.options.error_on_external_run = True
@@ -8,6 +10,11 @@
 @nox.session(python=[f"{py}3.{x}" for py in ("", "pypy") for x in range(10, 14)])
 def test(session: nox.Session) -> None:
     """Run tests."""
+    py_minor = int(cast(str, session.python).rpartition(".")[2])
+    if py_minor >= 13:  # noqa: PLR2004
+        session.env.update(
+            MULTIDICT_NO_EXTENSIONS="1",
+        )
     session.install(".[examples]", "-r", "requirements/test-requirements.txt")
 
     known_deprecations = [