Improve build workflow, prevent duplicate runs and verify datagen

.github/workflows/build.yml

@@ -1,15 +1,24 @@
 name: Build
+
 on:
   pull_request:
+    # Only on branches, not tags/releases
+    branches: ["**"]
   push:
+    branches: ["*"]
   release:
     types: [published]
 
 permissions:
   contents: write
 
+concurrency:
+  group: ci-build-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.repository
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
@@ -23,6 +32,14 @@ jobs:
           distribution: 'temurin'
       - name: Set up Gradle
         uses: gradle/actions/setup-gradle@v3
+      - name: Generate assets
+        run: ./gradlew runData
+      - name: Check that data was generated
+        run: test -d ./src/generated/resources/.cache
+      - name: Ensure generated data is up-to-date
+        run: |
+          git status
+          if [ -n "$(git status --porcelain)" ]; then exit 1; fi
       - name: Build release files
         env:
           MEGA_VERSION: ${{ github.event.release.tag_name }}

.gitignore

@@ -21,3 +21,4 @@ build
 eclipse
 run
 .directory
+src/generated/resources/.cache