Update gradle/actions action to v6

Author: renovate[bot]

.github/workflows/gradle-build.yml

@@ -12,7 +12,7 @@ jobs:
     if: "!contains(github.event.commits[0].message, '[ci-skip]')"
     steps:
       - uses: actions/checkout@v6
-      - uses: gradle/actions/wrapper-validation@v5
+      - uses: gradle/actions/wrapper-validation@v6
       - name: Set up JDK 17
         uses: actions/setup-java@v5
         with:

.github/workflows/publish.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6.0.2
-      - uses: gradle/actions/wrapper-validation@v5
+      - uses: gradle/actions/wrapper-validation@v6
       - name: Set up JDK 17
         uses: actions/setup-java@v5.2.0
         with: