ci: replace 'source' with PATH/VIRTUAL_ENV exports for dash compatibility

The runner's default shell is /bin/sh (dash), which has no 'source' builtin.

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

Author: mgehre-amd

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

@@ -194,7 +194,8 @@ jobs:
           # first, which breaks `uv pip install --system`.
           uv venv --python 3.12 "$GITHUB_WORKSPACE/.venv"
           echo "$GITHUB_WORKSPACE/.venv/bin" >> "$GITHUB_PATH"
-          source "$GITHUB_WORKSPACE/.venv/bin/activate"
+          export PATH="$GITHUB_WORKSPACE/.venv/bin:$PATH"
+          export VIRTUAL_ENV="$GITHUB_WORKSPACE/.venv"
           # Pin torch from the nightly ROCm index *only* (no PyPI
           # fallback) so we always get the ROCm wheel.
           uv pip install \