Update gradle-test.yml

Author: burdoto

.github/workflows/gradle-test.yml

@@ -11,8 +11,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - name: Checkout repository
+      - name: Checkout repository (with submodules)
         uses: actions/checkout@v4
+        with:
+          submodules: recursive   # or true if you only need first-level
+          fetch-depth: 0          # ensures full history for submodules
 
       - name: Set up JDK 21
         uses: actions/setup-java@v4