Add separate GH workflow for pull requests

.github/workflows/maven-pr.yml

@@ -0,0 +1,21 @@
+name: Pull request workflow
+on:
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up JDK
+      uses: actions/setup-java@v4
+      with:
+        distribution: 'temurin'
+        java-version: '17'
+        cache: 'maven'
+
+    - name: Build with Maven
+      run: mvn -B package --file pom.xml

.github/workflows/maven.yml

@@ -2,8 +2,7 @@ name: Java CI with Maven
 on:
   push:
     branches: [ master ]
-  pull_request:
-    branches: [ master ]
+  workflow_dispatch:
 
 jobs:
   build:
@@ -13,7 +12,7 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Set up JDK
-      uses: actions/setup-java@v3
+      uses: actions/setup-java@v4
       with:
         distribution: 'temurin'
         java-version: '17'