Fixed Typo (#2016)

Fixes #2013.

### Description
This fixes a minor typo in one notebook.

### Checks
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [ ] Avoid including large-size files in the PR.
- [ ] Clean up long text outputs from code cells in the notebook.
- [ ] For security purposes, please check the contents and remove any
sensitive info such as user names and private key.
- [ ] Ensure (1) hyperlinks and markdown anchors are working (2) use
relative paths for tutorial repo files (3) put figure and graphs in the
`./figure` folder
- [ ] Notebook runs automatically `./runner.sh -t <path to .ipynb file>`

Signed-off-by: Eric Kerfoot <17726042+ericspod@users.noreply.github.com>

Author: ericspod

3d_segmentation/spleen_segmentation_3d_visualization_basic.ipynb

@@ -484,7 +484,7 @@
     "# standard PyTorch program style: create UNet, DiceLoss and Adam optimizer\n",
     "device = torch.device(\"cuda:0\")\n",
     "\n",
-    "UNet_meatdata = {\n",
+    "UNet_metadata = {\n",
     "    \"spatial_dims\": 3,\n",
     "    \"in_channels\": 1,\n",
     "    \"out_channels\": 2,\n",
@@ -494,7 +494,7 @@
     "    \"norm\": Norm.BATCH,\n",
     "}\n",
     "\n",
-    "model = UNet(**UNet_meatdata).to(device)\n",
+    "model = UNet(**UNet_metadata).to(device)\n",
     "loss_function = DiceLoss(to_onehot_y=True, softmax=True)\n",
     "loss_type = \"DiceLoss\"\n",
     "optimizer = torch.optim.Adam(model.parameters(), 1e-4)\n",
@@ -539,7 +539,7 @@
     "# initialize a new Aim Run\n",
     "aim_run = aim.Run()\n",
     "# log model metadata\n",
-    "aim_run[\"UNet_meatdata\"] = UNet_meatdata\n",
+    "aim_run[\"UNet_metadata\"] = UNet_metadata\n",
     "# log optimizer metadata\n",
     "aim_run[\"Optimizer_metadata\"] = Optimizer_metadata\n",
     "\n",