fix[hardware_predict]: Fixed hardcoded output directory

Author: Djokzer

hls4ml/backends/vitis_accelerator/vitis_accelerator_backend.py

@@ -157,7 +157,7 @@ def hardware_predict(self, model, x, target="hw", debug=False, profilingRepeat=-
             X_test_flat = X_test_flat.ctypes.data_as(ctypes.POINTER(ctypes.c_double))
 
             # Change working directory to the HLS project directory
-            os.chdir('model_va/hls4ml_prj')
+            os.chdir(model.config.get_output_dir())
 
             # Check if the shared library exists
             if not os.path.exists('./lib_host.so'):