github: add github build action

Author: kofemann

.github/workflows/build.yml

@@ -0,0 +1,21 @@
+name: Build and Test
+
+on:
+  push:
+  pull_request:
+    types: [opened, reopened]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: maven
+      - name: Build with Maven
+        run: mvn --batch-mode --update-snapshots package
+