trigger workflow tutorials

tutorials/tutorial13/tutorial.ipynb

@@ -19,7 +19,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -38,7 +38,7 @@
     "import warnings\n",
     "\n",
     "from pina import Condition, Trainer\n",
-    "from pina.problem import SpatialProblem\n",
+    "from pina.problem import SpatialProblem \n",
     "from pina.operator import laplacian\n",
     "from pina.solver import PINN, SelfAdaptivePINN as SAPINN\n",
     "from pina.loss import LpLoss\n",