Install xmlstarlet

Author: leonardehrenfried

.github/workflows/maven.yml

@@ -6,12 +6,17 @@ on:
   pull_request:
     branches: [ "master" ]
 
+env:
+  MAVEN_ARGS: "--no-transfer-progress -Dstyle.color=always"
+
 jobs:
   build:
 
     runs-on: ubuntu-latest
 
     steps:
+    - run: |
+        sudo apt-get install xmlstarlet -yq
     - uses: actions/checkout@v4
     - name: Set up JDK 17
       uses: actions/setup-java@v4