update workflow

.github/workflows/unit_tests.yml

@@ -41,6 +41,7 @@ jobs:
           - os: windows-latest
             python-version: '3.9.13'
     runs-on: ${{ matrix.os }}
+
     # Service containers to run with `runner-job`
     services:
       # Label used to access the service container
@@ -63,6 +64,8 @@ jobs:
           run-poetry-install: true
           create-venv-at-path: .venv
       - name: Run unit tests
+          # Run the macOS job only on merge to the main branch
+        if:  matrix.os != 'macos-12' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
         run: |
           export PYTHONUNBUFFERED=1
           poetry run pytest tests/units --cov --no-cov-on-fail --cov-report=
@@ -74,6 +77,7 @@ jobs:
           poetry run pytest tests/units --cov --no-cov-on-fail --cov-report=
       # Change to explicitly install v1 when reflex-hosting-cli is compatible with v2
       - name: Run unit tests w/ pydantic v1
+        if:  matrix.os != 'macos-12' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
         run: |
           export PYTHONUNBUFFERED=1
           poetry run uv pip install "pydantic~=1.10"