ci: models don't contain mvnw (#2411)

Author: rsynek

.github/workflows/downstream_build.yml

@@ -111,7 +111,7 @@ jobs:
         shell: bash
         env:
           TIMEFOLD_LICENSE: ${{ secrets.TIMEFOLD_SOLVER_CI_PROD_LICENSE }}
-        run: ./mvnw -B clean verify
+        run: mvn -B clean verify
 
       - name: Test Summary
         uses: test-summary/action@2920bc1b1b377c787227b204af6981e8f41bbef3