Update actions/checkout

Author: dstein64

.github/workflows/build.yml

@@ -24,7 +24,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         # When the ref is empty, HEAD will be checked out.
         ref: ${{ github.event.inputs.git-ref }}