ci: introduce GitHub Actions to verify Gradle wrapper

Signed-off-by: Kengo TODA <skypencil@gmail.com>

Author: KengoTODA

.github/workflows/build.yml

@@ -0,0 +1,17 @@
+on:
+  pull_request: {}
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: gradle/actions/wrapper-validation@v3
+      - uses: gradle/actions/setup-gradle@v3
+      - run: ./gradlew build
+      - uses: actions/upload-artifact@v4
+        with:
+          path: build/reports