Update CI action versions.

Author: vsajip

.github/workflows/tests.yml

@@ -40,9 +40,9 @@ jobs:
             python-version: '3.7'
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
     - name: Add Homebrew to PATH (Ubuntu)