ci(py-versions): remove versions not needed

Author: project-delphi

.github/workflows/ci.yml

@@ -9,17 +9,14 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        python-version: ["3.9", "3.10", "3.11"]
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up Python ${{ matrix.python-version }}
+      - name: Set up Python 3.10
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: "3.10"
           cache: "pip"
 
       - name: Install dependencies