comment save notebook in mmm example (pymc-labs#1053)

Author: juanitorduz

docs/source/notebooks/mmm/mmm_example.ipynb

@@ -10475,7 +10475,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "mmm.save(\"model.nc\")"
+    "# mmm.save(\"model.nc\")"
    ]
   },
   {
@@ -10532,7 +10532,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.14"
+   "version": "3.12.4"
   },
   "toc": {
    "base_numbering": 1,