chore(deps): update actions/setup-java action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: Set up JDK 21
-      uses: actions/setup-java@v4
+      uses: actions/setup-java@v6
       with:
         java-version: '21'
         distribution: 'temurin'