update checkout version

Signed-off-by: Karl W. Schulz <karl.schulz@amd.com>

.github/workflows/ubuntu-focal.yml

@@ -32,7 +32,7 @@ jobs:
           sudo apt-get install -y locales
           sudo locale-gen en_US.UTF-8
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Install Python prereqs
         run: |
           python3 -m pip install -r requirements.txt