ci: keep test reports

Author: SpyrosKou

.github/workflows/build.yml

@@ -40,3 +40,14 @@ jobs:
 
     - name: Build with Gradle Wrapper
       run: ./gradlew build
+
+    - name: Upload test reports
+      uses: actions/upload-artifact@v4
+      if: always()
+      with:
+        name: test-reports
+        path: |
+          **/build/reports/tests/**
+          **/build/test-results/**
+        if-no-files-found: warn
+        retention-days: 15