Add pybind11 and use --no-build-isolation for PyG extensions

The PyG extensions (torch-scatter, torch-sparse, etc.) need to see the
installed torch package during their build. Adding pybind11 and disabling
build isolation ensures they can locate the necessary dependencies.

Dockerfile

@@ -62,9 +62,10 @@ RUN pip install --no-cache-dir \
 ENV ROCM_HOME=/opt/rocm
 ENV HIP_HOME=/opt/rocm
 
-RUN pip install --no-cache-dir torch-geometric==2.4.0
+RUN pip install --no-cache-dir torch-geometric==2.4.0 pybind11
 
-RUN pip install --no-cache-dir \
+# Build PyG extensions with no build isolation so they can see torch
+RUN pip install --no-cache-dir --no-build-isolation \
     torch-scatter==2.1.2 \
     torch-sparse==0.6.18 \
     torch-cluster==1.6.2 \