[core] fix sleep mode in pytorch 2.6

[youkaichao]

as observed in #12721 , Basic Correctness case basic_correctness/test_cumem.py::test_end_to_end[meta-llama/Llama-3.2-1B-Instruct] has a segfault due to enable_sleep_mode=True , but another test with opt-125m passed.

I locally tested that this fixes the bug in pytorch 2.6

[github-actions]

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[mgoin]

Thank you for looking into this 🙏