Tests: Update for the modern day and drop Python 2.7

.github/workflows/testing.yml

@@ -26,19 +26,16 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9, '3.10']
+        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
         no-coverage: [0]
         include:
           - os: ubuntu-latest
-            python-version: pypy-2.7
-            no-coverage: 1
-          - os: ubuntu-latest
-            python-version: pypy-3.6
+            python-version: pypy-3.10
             no-coverage: 1
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Set up Python Env
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
       - name: Display Python version