fix(tests): pin python<3.0

With Cython 3.0, on github actions:
- All openmp tests fail on windows.
- Elliptical drop with openmp fails on ubuntu due to timeout.
- All openmp tests pass on macos runner
- test_compressed_octree_has_lesser_depth_than_octree fails

Pinning cython<3.0 to fix these failures.

.github/workflows/tests.yml

@@ -39,7 +39,7 @@ jobs:
       - name: Install dependencies
         run: |
           conda info
-          conda install -c conda-forge numpy cython h5py
+          conda install -c conda-forge numpy 'cython<3.0' h5py
           python -m pip install --upgrade pip setuptools wheel
           python -m pip install https://github.com/pypr/cyarray/zipball/master
           python -m pip install https://github.com/pypr/compyle/zipball/master

.github/workflows/zoltan-tests.yml

@@ -40,7 +40,7 @@ jobs:
       - name: Install dependencies
         run: |
           conda info
-          conda install -c conda-forge numpy cython
+          conda install -c conda-forge numpy 'cython<3.0'
           python -m pip install --upgrade pip setuptools wheel
           python -m pip install mpi4py
           python -m pip install https://github.com/pypr/cyarray/zipball/master

pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "Beaker",
-    "Cython>=0.20",
+    "Cython<3.0",
     "compyle>=0.8",
     "cyarray",
     "mako",

requirements.txt

@@ -1,6 +1,6 @@
 numpy
 setuptools>=42.0.0
-Cython>=0.20
+Cython<3.0
 cyarray
 compyle>=0.8
 mako

setup.py

@@ -681,7 +681,7 @@ def setup_package():
 
     # The requirements.
     install_requires = [
-        'numpy', 'mako', 'cyarray', 'compyle>=0.8', 'Cython>=0.20',
+        'numpy', 'mako', 'cyarray', 'compyle>=0.8', 'Cython<3.0',
         'setuptools>=42.0.0', 'pytools', 'Beaker'
     ]
     tests_require = ['pytest>=3.0', 'h5py', 'vtk']