CI(GHActions): Use `conda` to install older Pythons

Ubuntu >= 22 and `setup-python` dropped Pythons < 3.7.
Use `s-weigand/setup-conda` instead of `setup-python`.

diff --git a/.github/workflows/run-tests.yaml b/.github/workflows/run-tests.yaml
index 7a344820e2e6cb5a336579075016cfdd0e5ce0f6..b0dfacf4013f12cd57606ce47263922511c2576b 100644 (file)
--- a/.github/workflows/run-tests.yaml
+++ b/.github/workflows/run-tests.yaml
@@ -27,9 +27,14 @@ jobs:
 
       # Setup Python/pip
       - uses: actions/checkout@v2
+      - uses: s-weigand/setup-conda@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+        if: ${{ runner.os == 'Linux' && matrix.python-version != '3.11' }}
       - uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
+        if: ${{ runner.os != 'Linux' || matrix.python-version == '3.11' }}
       - name: Cache pip
         uses: actions/cache@v3
         with: