CI: Add Extra Example Requirements (CPU)

.github/workflows/dependencies/gcc-openmpi.sh

@@ -28,4 +28,5 @@ python3 -m pip install -U cmake pytest
 python3 -m pip install -U -r requirements_mpi.txt
 python3 -m pip install -U -r examples/requirements.txt
 
-python3 -m pip install -U openPMD-validator
+# extra tests
+python3 -m pip install -U -r examples/requirements_extra.txt

.github/workflows/dependencies/gcc.sh

@@ -27,4 +27,5 @@ python3 -m pip install -U cmake pytest
 python3 -m pip install -U -r requirements.txt
 python3 -m pip install -U -r examples/requirements.txt
 
-python3 -m pip install -U openPMD-validator
+# extra tests
+python3 -m pip install -U -r examples/requirements_extra.txt

examples/requirements_extra.txt

@@ -0,0 +1,10 @@
+# This is for CPU CI tests with extra requirements.
+#
+# For PyTorch, see alternative packages, e.g., for GPU here:
+# https://pytorch.org/get-started/locally/
+-i https://download.pytorch.org/whl/cpu
+
+-r requirements.txt
+
+openPMD-validator
+torch