ci: refine build, benchmark, and Pages workflows

* add workflow-level concurrency control for benchmark and Pages pipelines
* keep release changelog generation and the separate distZip step in the build workflow by design
* align the benchmark workflow with the primary Gradle action setup
* add Gradle wrapper validation to benchmark runs
* switch benchmark caching and setup to gradle/actions/setup-gradle
* remove the redundant Gradle wrapper executable-bit adjustment
* keep benchmark generation in Pages unchanged while improving workflow control

.github/workflows/benchmarks.yml

@@ -19,6 +19,10 @@ on:
       - 'gradlew.bat'
       - '.github/workflows/benchmarks.yml'
 
+concurrency:
+  group: benchmarks-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   jmh:
     runs-on: ubuntu-latest
@@ -31,15 +35,17 @@ jobs:
       - name: Check out sources
         uses: actions/checkout@v4
 
+      - name: Validate Gradle wrapper
+        uses: gradle/actions/wrapper-validation@v4
+
       - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
           distribution: temurin
           java-version: '21'
-          cache: gradle
 
-      - name: Make Gradle executable
-        run: chmod +x ./gradlew
+      - name: Set up Gradle caching and instrumentation
+        uses: gradle/actions/setup-gradle@v4
 
       - name: Verify reproducibility inputs
         shell: bash