[py] Update test os matrix

Author: cgoldberg

.github/workflows/ci-python.yml

@@ -64,6 +64,7 @@ jobs:
         include:
           - os: ubuntu
           - os: windows
+          - os: macos
     with:
       name: Unit Tests (${{ matrix.os }})
       os: ${{ matrix.os }}
@@ -103,8 +104,6 @@ jobs:
             os: windows
           - browser: edge
             os: windows
-          - browser: firefox
-            os: windows
     with:
       name: Integration Tests (${{ matrix.browser }}, ${{ matrix.os }})
       browser: ${{ matrix.browser }}