ci: reference gradle/gradle-build-action by version

There is no reason to use a specific commit hash.

.github/workflows/gradle.yml

@@ -1,7 +1,3 @@
-# This workflow uses actions that are not certified by GitHub.
-# They are provided by a third-party and are governed by
-# separate terms of service, privacy policy, and support
-# documentation.
 # This workflow will build a Java project with Gradle and cache/restore any dependencies to improve the workflow execution time
 # For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-gradle
 
@@ -31,7 +27,7 @@ jobs:
         distribution: 'temurin'
         cache: 'gradle'
     - name: Build with Gradle
-      uses: gradle/gradle-build-action@842c587ad8aa4c68eeba24c396e15af4c2e9f30a
+      uses: gradle/gradle-build-action@v2
       with:
         arguments: build
       env: