FIX: Provide FD arguments to combined plot function in BOLD notebook

Provide FD arguments to combined plot function in BOLD notebook.

Fixes:
```
File "/home/runner/work/nifreeze/nifreeze/docs/notebooks/bold_realignment.py", line 275, in main
    plot_combined_profile(
TypeError: main.<locals>.plot_combined_profile() missing 2 required positional arguments: 'afni_fd' and 'nifreeze_fd'
```

raised for example in:
https://github.com/nipreps/nifreeze/actions/runs/15007162520/job/42168515561?pr=117#step:14:2223

Take advantage of the commit to rename the function definition variables
so that they do not shadow the outer variables.

Author: jhlegarreta

docs/notebooks/bold_realignment.ipynb

@@ -245,7 +245,7 @@
     "\n",
     "\n",
     "def plot_combined_profile(\n",
-    "    images, afni_fd, nifreeze_fd, indexing=None, figsize=(15, 1.7), cmap=\"gray\", labels=None\n",
+    "    images, _afni_fd, _nifreeze_fd, indexing=None, figsize=(15, 1.7), cmap=\"gray\", labels=None\n",
     "):\n",
     "    # Calculate the number of profile plots\n",
     "    n_images = len(images)\n",
@@ -258,7 +258,7 @@
     "    )\n",
     "\n",
     "    # Plot the framewise displacement on the first axis\n",
-    "    fd = pd.DataFrame({\"afni\": afni_fd, \"nifreeze\": nifreeze_fd})\n",
+    "    fd = pd.DataFrame({\"afni\": _afni_fd, \"nifreeze\": _nifreeze_fd})\n",
     "    fd_axis = axes[0]\n",
     "    _ = plot_framewise_displacement(fd, [\"AFNI 3dVolreg FD\", \"nifreeze FD\"], ax=fd_axis)\n",
     "\n",
@@ -298,6 +298,8 @@
    "source": [
     "plot_combined_profile(\n",
     "    (DATA_PATH / bold_runs[15], afni_realigned[15], afni_realigned[15]),\n",
+    "    afni_fd,\n",
+    "    nifreeze_fd,\n",
     "    labels=(\"hmc1\", \"original\", \"hmc2\"),\n",
     ");"
    ]