Use macos-13 not macos-latest for downstream tests

.github/workflows/downstream.yml

@@ -1,70 +1,70 b''
 name: Run Downstream tests
 
 on:
   push:
   pull_request:
   # Run weekly on Monday at 1:23 UTC
   schedule:
   - cron:  '23 1 * * 1'
   workflow_dispatch:
 
 permissions:
   contents: read
 
 jobs:
   test:
     runs-on: ${{ matrix.os }}
     # Disable scheduled CI runs on forks
     if: github.event_name != 'schedule' || github.repository_owner == 'ipython'
     strategy:
       matrix:
         os: [ubuntu-latest]
         python-version: ["3.10"]
         include:
-          - os: macos-latest
+          - os: macos-13
             python-version: "3.10"
 
     steps:
     - uses: actions/checkout@v3
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Update Python installer
       run: |
         python -m pip install --upgrade pip setuptools wheel
     - name: Install ipykernel
       run: |
         cd ..
         git clone https://github.com/ipython/ipykernel
         cd ipykernel
         pip install -e .[test]
         cd ..
     - name: Install and update Python dependencies
       run: |
         python -m pip install --upgrade -e file://$PWD#egg=ipython[test]
         # we must install IPython after ipykernel to get the right versions.
         python -m pip install --upgrade --upgrade-strategy eager flaky ipyparallel
     - name: pytest ipykernel
       env:
         COLUMNS: 120
       run: |
         cd ../ipykernel
         pytest
     - name: Install sagemath-repl
       run: |
         cd ..
         git clone --depth 1 https://github.com/sagemath/sage
         cd sage
         # We cloned it for the tests, but for simplicity we install the
         # wheels from PyPI.
         # (Avoid 10.3b6 because of https://github.com/sagemath/sage/pull/37178)
         pip install --pre "sagemath-repl<10.3b6" "sagemath-environment<10.3b6"
         # Install optionals that make more tests pass
         pip install sagemath-categories pillow
         cd ..
     - name: Test sagemath-repl
       run: |
         cd ../sage/
         # From https://github.com/sagemath/sage/blob/develop/pkgs/sagemath-repl/tox.ini
         sage-runtests -p --environment=sage.all__sagemath_repl --baseline-stats-path=pkgs/sagemath-repl/known-test-failures.json --initial --optional=sage src/sage/repl src/sage/doctest src/sage/misc/sage_input.py src/sage/misc/sage_eval.py