Readd upper bound on NumPy version

Author: matt-graham

.github/workflows/tests.yml

@@ -56,7 +56,7 @@ jobs:
       # by installing torch and healpy using conda
       # https://github.com/healpy/healpy/issues/1012
       run: |
-        conda install jax "jax>=0.3.13,<0.6.0" "numpy>=1.20" ducc0 healpy pytorch pytest pytest-cov
+        conda install jax "jax>=0.3.13,<0.6.0" "numpy>=1.20,<2" ducc0 healpy pytorch pytest pytest-cov
         python -m pip install --upgrade pip
         pip install --no-deps so3 pyssht
         pip install --no-deps .