[release/2.12] Fix Windows cross-drive HIPIFY failure in CUDAExtension (ROCM-24803)

[ethanwee1]

https://amd-hub.atlassian.net/browse/ROCM-24803

Split from ROCm/pytorch#3382. Fixes Windows cross-drive HIPIFY failure in CUDAExtension by realpath-normalizing build dir and hipified sources before os.path.relpath().

Required for torchaudio GPU extension builds on TheRock Windows runners (B: subst aliasing C:).

Validation: included in TheRock build on ew/rocm-24803-validation.

[ethanwee1]

Rebased stack ready for review. TheRock Windows gfx110X-all validation build (pin + cpp_extension fix on ew/rocm-24803-validation):

Run: https://github.com/ROCm/TheRock/actions/runs/31709842398

Input	Value
pytorch_git_ref	ew/rocm-24803-validation
amdgpu_families	gfx110X-all
test_amdgpu_families	gfx110X-all
python_version	3.12
rocm_version	7.14.0a20260624
rocm_package_index_url	https://rocm.nightlies.amd.com/whl-multi-arch/

PR split (ROCM-24803):

• This PR — related_commits pin only (rebased onto release/2.12)
• ROCm/pytorch#3562 — Windows B:/C: CUDAExtension realpath fix
• ROCm/audio#17 — source-only HIP port @ a0da46b3 on release/2.11.0.1

cc @jithunnair-amd @pablo-garay for review

[ethanwee1]

Build failure analysis for run 31709842398:

Not a PyTorch/torchaudio code issue. The build died in Install requirements before checkout/build started:

choco install --no-progress -y ninja --version 1.13.1
A newer version of ninja (v1.13.2) is already installed.
Chocolatey installed 0/1 packages. 1 packages failed.

The windows-2022 runner image was updated (20260802.262) and now ships ninja 1.13.2, while TheRock main still pins 1.13.1 via chocolatey (which refuses downgrade).

Redispatch using Pablo's ninja-tolerant workflow branch (same fix as users/garayp/win-ninja-tolerant) + the ROCm version from the July passing build:

New run: https://github.com/ROCm/TheRock/actions/runs/31711078734

Input	Value
repository / ref	ROCm/TheRock @ users/garayp/win-ninja-tolerant
rocm_version	7.14.0.dev0+331251018497de4049c7d8447c7b2d1dcdfd012e (same as 28953516514)
pytorch_git_ref	ew/rocm-24803-validation