[3.12] gh-101100: Fix sphinx warnings in c-api/file.rst (GH-114546)

[miss-islington]

(cherry picked from commit 01d970c)

Co-authored-by: Nikita Sobolev mail@sobolevn.me
Co-authored-by: Hugo van Kemenade 1324225+hugovk@users.noreply.github.com

• Issue: Fix all Sphinx reference warnings in the documentation #101100

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📚 Documentation preview 📚: https://cpython-previews--114584.org.readthedocs.build/

[hugovk]

@sobolevn Please could you check the error?

Error: must not contain warnings: Doc/c-api/object.rst 291: c:identifier reference target not found: Py_hash_t 303: c:identifier reference target not found: Py_hash_t 

Ideally to fix the warnings, but if it's not trivial, for backport branches I think it would be okay to put that file back in .nitignore.

[sobolevn]

Will do

[sobolevn]

Done! 👍

[hugovk]

Thanks!