Display warning only when ROCm version is less than Pytorch required version

[Inokinoki]

Purpose

During my build for AMD HIP, I saw:

-- Found Torch: /home/inoki/Projects/Builds/test-pytorch/.venv/lib/python3.11/site-packages/torch/lib/libtorch.so  
-- The HIP compiler identification is Clang 19.0.0
-- Detecting HIP compiler ABI info
-- Detecting HIP compiler ABI info - done
-- Check for working HIP compiler: /opt/rocm-6.4.0/lib/llvm/bin/clang++ - skipped
-- Detecting HIP compile features
-- Detecting HIP compile features - done
CMake Warning at CMakeLists.txt:140 (message):
  Pytorch version >= 2.9.0 expected for ROCm build, saw 2.9.1 instead.

where the warning seems to be confusing

Test Plan

Test Result

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• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
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[gemini-code-assist]

Code Review

This pull request correctly addresses an issue with a confusing warning message during ROCm builds. The previous logic incorrectly triggered a warning when the PyTorch version was newer than the minimum required version. The change modifies the CMake version check from NOT VERSION_EQUAL to VERSION_LESS, which aligns the logic with the warning message's intent of ensuring a minimum PyTorch version. The fix is accurate and resolves the reported problem.