Backport PR #13182: ci: Simplify CI maintenance by combining Ubuntu and macOS workflows

.github/workflows/test.yml

@@ -1,36 +1,50 b''
 name: Run tests
 
-on: [push, pull_request]
+on:
+  push:
+  pull_request:
+  # Run weekly on Monday at 1:23 UTC
+  schedule:
+  - cron:  '23 1 * * 1'
+  workflow_dispatch:
+
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [3.7, 3.8, 3.9]
+        os: [ubuntu-latest]
+        python-version: ["3.7", "3.8", "3.9"]
+        # Test all on ubuntu, test ends on macos
+        include:
+          - os: macos-latest
+            python-version: "3.7"
+          - os: macos-latest
+            python-version: "3.9"
 
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v2
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install and update Python dependencies
       run: |
         python -m pip install --upgrade pip setuptools wheel
         python -m pip install --upgrade -e file://$PWD#egg=ipython[test]
         python -m pip install --upgrade --upgrade-strategy eager trio curio 
         python -m pip install --upgrade pytest pytest-trio 'matplotlib!=3.2.0'
         python -m pip install --upgrade check-manifest pytest-cov anyio
     - name: Check manifest
       run: check-manifest
     - name: iptest
       run: |
         cd /tmp && iptest --coverage xml && cd -
         cp /tmp/ipy_coverage.xml ./
         cp /tmp/.coverage ./
     - name: pytest
       run: |
         pytest
     - name: Upload coverage to Codecov
       uses: codecov/codecov-action@v1