ci(main): run tests for both ubuntu-latest and macos-latest

Author: ljgray

.github/workflows/main.yml

@@ -39,22 +39,32 @@ jobs:
 
     strategy:
       matrix:
+        os: [ubuntu-latest, macos-latest]
         python-version: ["3.9", "3.12"]
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
 
     - name: Install apt dependencies
+      if: matrix.os == 'ubuntu-latest'
       run: |
         sudo apt-get update
         sudo apt-get install -y libopenmpi-dev openmpi-bin libhdf5-serial-dev
 
+    - name: Install brew dependencies
+      if: matrix.os == 'macos-latest'
+      run: |
+        brew install open-mpi hdf5
+
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
 
+    - name: Update pip
+      run: pip install --upgrade pip
+
     - name: Install pip dependencies
       run: |
         pip install -e .[compression,mpi,test]