Linux needs Maven too

Author: fabapp2

.github/workflows/build-linux.yml

@@ -14,6 +14,9 @@ jobs:
       fail-fast: false
     name: CI Build Linux
     steps:
+      - uses: jvalkeal/setup-maven@v1
+        with:
+          maven-version: 3.6.3
       - uses: actions/checkout@v4
       - uses: actions/setup-java@v4
         with: