chore: Add GH Action to check that the demo projects compile correctly

.github/workflows/build.yml

@@ -0,0 +1,52 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    env:
+      JAVA_OPTS: "-Xmx4G"
+      SBT_OPTS: "-Dsbt.ci=true"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup JDK
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'zulu'
+          java-version: '21'
+
+      - name: Build Java Maven
+        working-directory: java/maven
+        run: ./mvnw --batch-mode -Dstyle.color=always --no-transfer-progress test-compile
+
+      - name: Build Java Gradle
+        working-directory: java/gradle
+        run: ./gradlew gatlingClasses
+
+      - name: Build Kotlin Maven
+        working-directory: kotlin/maven
+        run: ./mvnw --batch-mode -Dstyle.color=always --no-transfer-progress test-compile
+
+      - name: Build Kotlin Gradle
+        working-directory: kotlin/gradle
+        run: ./gradlew gatlingClasses
+
+      - name: Build Scala sbt
+        working-directory: scala/sbt
+        run: sbt Gatling/compile