chore(deps): update actions/setup-java action to v4 (#273)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci-backend.yml

@@ -30,7 +30,7 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: Set up JDK 21
-      uses: actions/setup-java@v3
+      uses: actions/setup-java@v4
       with:
         java-version: '21'
         distribution: 'temurin'

.github/workflows/release-please.yml

@@ -190,7 +190,7 @@ jobs:
         working-directory: playground-backend
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-java@v3
+      - uses: actions/setup-java@v4
         with:
           java-version: '21'
           distribution: 'temurin'