fix torch-numpy dependency in github workflows

Author: cw-tan

.github/workflows/tests.yml

@@ -31,6 +31,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install setuptools wheel
+        if [ ${TORCH} == 1.13.1 ]; then pip install numpy==1.26.4; fi  # older torch versions fail with numpy 2
         pip install torch==${TORCH} -f https://download.pytorch.org/whl/cpu/torch_stable.html
         pip install h5py scikit-learn  # install packages that aren't required dependencies but that the tests do need
         pip install  --upgrade-strategy only-if-needed .