Update actions/checkout to v4 for compatibility

Co-authored-by: lippytm <65956507+lippytm@users.noreply.github.com>

Author: Copilot

.github/workflows/blank.yml

@@ -37,7 +37,7 @@ jobs:
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       # Runs a single command using the runners shell
       - name: Run a one-line script