split build & pr workflows

limit build concurrency

.github/workflows/maven-build.yml

@@ -0,0 +1,25 @@
+name: Build & Check
+
+on:
+  push:
+    branches: [ master ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+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: Unshallow
+        run: git fetch --unshallow --quiet
+      - name: Build
+        run: mvn clean package

.github/workflows/maven-checker.yml → .github/workflows/maven-pr.yml

@@ -1,8 +1,6 @@
-name: Build & Check
+name: Build PR
 
 on:
-  push:
-    branches: [ master ]
   pull_request:
     branches: [ master ]