Update pr-validation.yml (#458)

* Update pr-validation.yml

* upgrade actions to v4 to address build warning "Node.js 16 actions are deprecated."
* use new embedded caching mechanism from actions/setup-java instead of manually caching with actions/cache
* add repository permissions required by dorny/test-reporter

* closes #404

.github/workflows/pr-validation.yml

@@ -14,7 +14,12 @@
 # specific language governing permissions and limitations under the License.
 #
 name: Java CI - Code tests
-on: [pull_request]
+on:
+  pull_request:
+permissions:
+  contents: read
+  actions: read
+  checks: write
 env:
   MAVEN_OPTS: >-
     -Dmaven.artifact.threads=4 
@@ -34,18 +39,13 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: 'Set up JDK 17'
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           java-version: '17'
           distribution: 'temurin'
-      - name: 'Cache Maven packages'
-        uses: actions/cache@v3
-        with:
-          path: ~/.m2
-          key: 'cache'
-          restore-keys: 'cache'
+          cache: 'maven'
       - name: 'Build and test with Maven'
         run: mvn verify
       - name: 'Report test results'