STYLE: Lint DWI GP estimation notebook

Lint DWI GP estimation notebook.

Take advantage of the commit to remove the unused random number
generator.

docs/notebooks/dwi_gp_estimation.ipynb

@@ -33,19 +33,6 @@
     "from scipy.ndimage import binary_dilation\n",
     "from skimage.morphology import ball\n",
     "\n",
-    "from nireports.reportlets.modality.dwi import plot_dwi"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "id": "69a3bc6b4fbe7036",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "seed = 1234\n",
-    "rng = np.random.default_rng(seed)\n",
-    "\n",
     "name = \"sherbrooke_3shell\"\n",
     "\n",
     "dwi_fname, bval_fname, bvec_fname = dpd.get_fnames(name=name)\n",
@@ -131,6 +118,8 @@
     }
    ],
    "source": [
+    "from nireports.reportlets.modality.dwi import plot_dwi\n",
+    "\n",
     "affine = nib.load(dwi_fname).affine\n",
     "plot_dwi(shell_data[..., dwi_vol_idx], affine, gradient=np.concatenate((np.squeeze(X_test), [1000])), output_file=\"sherbrooke_3shell_b1k_data.svg\")"
    ]