Update gradle/actions action to v6

Author: renovate[bot]

.github/workflows/app-build.yaml

@@ -22,7 +22,7 @@ jobs:
           distribution: temurin
           java-version: 21
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@0723195856401067f7a2779048b490ace7a47d7c # v5
+        uses: gradle/actions/setup-gradle@39e147cb9de83bb9910b8ef8bd7fff0ee20fcd6f # v6
       - name: Assemble debug APKs
         run: ./gradlew assembleDebug
       - name: Create publish bundle