Use actions/checkout@v3 for Gradle Wrapper Validation Action

See gh-29198

Author: izeye

.github/workflows/gradle-wrapper-validation.yml

@@ -9,5 +9,5 @@ jobs:
     name: "Validation"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: gradle/wrapper-validation-action@v1