chore(deps): update gradle/actions action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
           persist-credentials: false
 
       - name: Set up Gradle
-        uses: gradle/actions/setup-gradle@v5
+        uses: gradle/actions/setup-gradle@v6
 
       - name: Set up JDK 25
         uses: actions/setup-java@v5

.github/workflows/release.yml

@@ -28,7 +28,7 @@ jobs:
           persist-credentials: false
 
       - name: Set up Gradle
-        uses: gradle/actions/setup-gradle@v5
+        uses: gradle/actions/setup-gradle@v6
 
       - name: Set up JDK 25
         uses: actions/setup-java@v5