ci: pin uv pip install to python3.12 in test-kernels

The custom container-hook runner used by linux-strix-halo-gpu-rocm-oem
exec's commands with a PATH where /usr/bin/python3 (Debian 3.11, PEP 668
externally managed) precedes /usr/local/bin/python3 (3.12). uv pip
install --system then resolves the 3.11 interpreter and refuses with
"externally managed". Pass --python python3.12 explicitly so uv targets
the image's intended interpreter regardless of PATH ordering.

Signed-off-by: Matthias Gehre <matthias.gehre@amd.com>

Author: mgehre-amd

.github/workflows/build-rocm-wheels.yml

@@ -191,21 +191,24 @@ jobs:
 
       - name: Install wheel and test dependencies
         run: |
+          # The custom container-hook runner exec's commands with a PATH where
+          # /usr/bin/python3 (Debian 3.11, PEP 668 externally managed) precedes
+          # /usr/local/bin/python3 (3.12). Point uv at python3.12 explicitly.
           # Pin torch from the nightly ROCm index *only* (no PyPI
           # fallback) so we always get the ROCm wheel.
-          uv pip install --system \
+          uv pip install --system --python python3.12 \
             --upgrade-package torch \
             torch \
             --index-url ${{ env.PYTORCH_INDEX_URL }}
-          uv pip install --system dist/*.whl \
+          uv pip install --system --python python3.12 dist/*.whl \
             pytest pytest-timeout numpy \
             tblib transformers huggingface_hub sentencepiece pillow \
             --index-url ${{ env.PYTORCH_INDEX_URL }} \
             --extra-index-url https://pypi.org/simple/ \
             --index-strategy unsafe-first-match
           # Nightly torchvision has operator ABI mismatch with nightly torch.
           # Our kernel tests don't need it; remove to prevent conftest crash.
-          uv pip uninstall --system torchvision 2>/dev/null || true
+          uv pip uninstall --system --python python3.12 torchvision 2>/dev/null || true
 
       - name: Prepare test environment
         run: |