Sphinx documentation warning in later version

When building documentation using a later than curent version of sphinx (current is 7.2.6, later is 7.4.7) There is a warning that will need to be resovled:

```
${the/run/directory/}share/fcm_make_ants/build/docs/source/merge.rst:12: WARNING: underfined label: 'ancile_fill_n_merge.py'
make: *** [html] Error 1
```

I think this is because the page that is being linked to is generated automatically and therefore doesn't have a corresponding label.

Start with share/fcm_make_ants/build/docs/source/merge.rst at line 12 and reproduce the documentation build using Sphinx 7.4.7. Trace the link to ancile_fill_n_merge.py and determine how the generated page is referenced; done means the build completes without the undefined-label warning.

Written by the indexing model from the issue text.