Adapt CUDA device enumeration to current main

Update the newer foreign-context test to use the CUDA-visible device count and regenerate the Device stub after applying the original public PR #2533 change.

Author: rwgk

cuda_core/cuda/core/_device.pyi

@@ -500,6 +500,8 @@ class Device:
         tuple of Device
             A tuple containing instances of available devices.
         """
+    @classmethod
+    def _get_all_devices_from_cuda_driver(cls): ...
     def to_system_device(self) -> cuda.core.system.Device:
         """
         Get the corresponding :class:`cuda.core.system.Device` (which is used

cuda_core/tests/test_memory.py

@@ -757,7 +757,7 @@ def test_mr_deallocation_without_current_context(init_cuda, capsys, replace_stre
 @pytest.mark.parametrize("replace_stream", [False, True])
 def test_mr_deallocation_with_foreign_context(capsys, replace_stream):
     """MR-backed Buffer teardown switches away from an unrelated current context."""
-    if ccx_system.get_num_devices() < 2:
+    if len(Device.get_all_devices()) < 2:
         pytest.skip("Test requires at least 2 GPUs")
 
     alloc_dev = Device(0)