Update to actions/checkout@v4

Issue gh-1605

Author: sjohnr

.github/workflows/pr-build-workflow.yml

@@ -15,7 +15,7 @@ jobs:
         jdk: [17]
       fail-fast: false
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up JDK ${{ matrix.jdk }}
         uses: spring-io/spring-gradle-build-action@v2
         with: