Update cpuinfo and apply thread-safe deinitialization patch

[Vineeth Chelur (crvineeth97)]

Description

• Update pytorch/cpuinfo from 4628dc060ce4e82345dc166bbac875609db4ff69 to 66ee79c038d70dad9f08705b2c9b3e58f6d8f512, the latest commit on cpuinfo main as of August 27, 2026.
• Carry the thread-safe, reference-counted initialization and deinitialization changes from pytorch/cpuinfo#400 as one shared ORT patch used by both FetchContent and vcpkg.
• Reset Windows ARM64 cache-population state on each initialization so repeated DLL load/unload cycles cannot reuse stale cache indices.
• Scope XNNPACK's cpuinfo references to hardware discovery so XNNPACK-enabled ORT builds do not retain unmatched references during DLL unload.

The cpuinfo patch can be removed after pytorch/cpuinfo#400, including the ARM64 reinitialization fix, is merged and ORT updates to a revision containing it. The XNNPACK compatibility patch can be removed after the corresponding lifecycle fix is available upstream.

Motivation and Context

microsoft/onnxruntime#28245 integrated cpuinfo_deinitialize() after pytorch/cpuinfo#387 added it upstream. That implementation was later reverted by pytorch/cpuinfo#411 because initialization and deinitialization were not safe for multiple consumers.

Pinning the latest cpuinfo main without an ORT-side patch would therefore make cpuinfo_deinitialize() a no-op again. Carrying the corrected implementation keeps ORT independent of the pending upstream review while preserving safe cleanup during dynamic DLL unload.

Testing

• onnxruntime_cpuinfo_refcount_test covers sequential consumers, concurrent consumers, and reinitialization after final release.
• Verified this test fails against ORT main's pinned cpuinfo revision (4628dc060ce4e82345dc166bbac875609db4ff69) and passes against the patched revision (66ee79c038d70dad9f08705b2c9b3e58f6d8f512).
• onnxruntime_shared_lib_cpuinfo_dlopen_test repeatedly loads and unloads onnxruntime.dll, initializes cpuinfo through hardware discovery, exercises XNNPACK when enabled, and detects sustained Windows process-heap growth.
• Verified the FetchContent patch sequences for the default, Linux, and Windows ARM64/ARM64EC paths, plus the vcpkg patch sequence, apply with zero rejected hunks.