Increase allowed import time for Python 3.12+ (#10342)

(cherry picked from commit 755299d)

tests/test_imports.py

@@ -38,7 +38,7 @@ def test_web___all__(pytester: pytest.Pytester) -> None:
         # and even slower under pytest-xdist, especially in CI
         _XDIST_WORKER_COUNT * 100 * (1 if _IS_CI_ENV else 1.53)
         if _IS_XDIST_RUN
-        else 265
+        else 295
     ),
 }
 _TARGET_TIMINGS_BY_PYTHON_VERSION["3.13"] = _TARGET_TIMINGS_BY_PYTHON_VERSION["3.12"]