ci: add automatic release builds

.github/workflows/maven.yml

@@ -0,0 +1,36 @@
+name: Release Build
+on:
+  release:
+    types: [created]
+
+jobs:
+  build:
+    permissions:
+      contents: write
+    runs-on: ubuntu-latest
+    env:
+      GH_TOKEN: ${{ github.token }}
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+
+    - name: Set up JDK 21
+      uses: actions/setup-java@v4
+      with:
+        java-version: '21'
+        distribution: 'temurin'
+        cache: maven
+
+    - name: Build with Maven
+      run: mvn -B package --file pom.xml
+
+    - name: Update dependency graph
+      uses: advanced-security/maven-dependency-submission-action@571e99aab1055c2e71a1e2309b9691de18d6b7d6
+
+    - name: Upload assets to release
+      shell: bash
+      run: |
+        gh release upload ${{github.event.release.tag_name}} ./target/earthsmp-*.jar
+
+