Update checkout action version to 4

The actions/checkout is now updated to 4 to avoid Node.js 16
deprecation warning.

Signed-off-by: Pragadeeswaran Sathyanarayanan <pragadeeswaran.sathyanarayanan@ibm.com>

Author: psathyan

.github/workflows/test.yaml

@@ -9,7 +9,7 @@ jobs:
     name: Verify Jenkins jobs
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3 
+      - uses: actions/checkout@v4
       - name: build JJB container image
         run: docker build -t nfs-ganesha-ci-tests -f tests/Containerfile .
       - name: update Jenkins Jobs