Add CUDA version compatibility check

[Andy-Jost]

Summary

Adds a version compatibility check that warns users when cuda-bindings was compiled against a newer CUDA major version than the installed driver supports.

Changes

cuda-bindings

• Added check_cuda_version_compatibility() function in cuda/bindings/utils/_version_check.py
• Compares compile-time CUDA_VERSION vs runtime cuDriverGetVersion()
• Exported from cuda.bindings.utils
• Added comprehensive unit tests in tests/test_version_check.py

cuda-core

• Device.__new__ calls check_cuda_version_compatibility() after cuInit succeeds
• Imports the function directly from cuda.bindings.utils

Rationale

When cuda-bindings is built against CUDA 13 headers but the user's driver only supports CUDA 12, many features will silently fail or behave unexpectedly. This check provides early, clear feedback:

UserWarning: cuda-bindings was built against CUDA 13.0, but the installed driver 
only supports CUDA 12.8. Some features may not work correctly. Consider updating 
your NVIDIA driver. Set CUDA_PYTHON_DISABLE_VERSION_CHECK=1 to suppress this warning.

Design

• Provided by cuda-bindings: The version check implementation lives in cuda.bindings.utils since it checks cuda-bindings' compile-time version
• Invoked by cuda-core: Called when Device first triggers CUDA initialization
• Runs once: Uses a module-level flag to ensure the check runs only once per process
• Non-blocking: Warning only, does not prevent operation
• Suppressible: Set CUDA_PYTHON_DISABLE_VERSION_CHECK=1 to disable
• Major version only: No warning for minor version differences (handled by graceful degradation per PR #1409)

Future Work

We could not find a suitable place to invoke the version check automatically within cuda-bindings itself (e.g., hooking into cuInit), so the check is currently triggered by cuda-core. This may be revisited in the future.

Test Coverage

7 tests in cuda-bindings covering:

• No warning when driver is newer
• No warning when same major version
• Warning when compile major > driver major
• Warning only issued once per process
• Suppression via environment variable
• Silent handling of driver errors
• Silent handling of missing CUDA_VERSION attribute

Related Work

• Complements PR #1409 which handles graceful degradation for minor version mismatches

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[Andy-Jost]

/ok to test 7ce325c07b559e9a66472f5ba7a99fe980e17c09

[Andy-Jost]

/ok to test 1962e351a233d65f2288fd6d16a43f0b0b75d6ad

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[Andy-Jost]

/ok to test 73e5a4379fad3392c24499e245a521c86c53db42

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/ok to test https://github.com/NVIDIA/cuda-python/commit/acadb3183278aca6201be0d1b733c2eb03b57dd5

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/ok to test 3a5c210cd89c018dda27e6e659a36802b17bc077

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/ok to test 96532b226

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/ok to test a368e0f249b051ed43c4b099a327a7e107425e0b

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