ci: print out packages, test on CMake 3.20

Signed-off-by: Henry Schreiner <[email protected]>

Author: henryiii

.github/workflows/ci.yml

@@ -46,6 +46,9 @@ jobs:
         include:
           - python-version: pypy-3.10
             runs-on: ubuntu-latest
+          - python-version: "3.9"
+            runs-on: ubuntu-latest
+            cmake: "3.20.x"
 
     steps:
       - uses: actions/checkout@v4
@@ -57,6 +60,11 @@ jobs:
           python-version: ${{ matrix.python-version }}
           allow-prereleases: true
 
+      - uses: jwlawson/actions-setup-cmake@v2
+        if: matrix.cmake != ''
+        with:
+          cmake-version: ${{ matrix.cmake }}
+
       - uses: yezz123/setup-uv@v4
 
       - name: Install package