[BUG][PYTHON] fix setup.py when no paths are specified

[loic-seguin]

This PR is related to this issue #20090.
Looping on {{#apis}} in the setup.mustache is not needed I think because we already have the infos at the root level.
As a consequence the setup method is always present if no paths attribute is given inside the yaml.

TODO : We might need to do this also for the generator python-pydantic-v1...

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[wing328]

https://github.com/OpenAPITools/openapi-generator/actions/runs/11824698634/job/32968636666?pr=20098n

thanks for the PR. please follow step 3 to update the samples

[loic-seguin]

https://github.com/OpenAPITools/openapi-generator/actions/runs/11824698634/job/32968636666?pr=20098n

thanks for the PR. please follow step 3 to update the samples

Done ;)

[wing328]

Thanks for the PR but your commit (as shown in the Commits tab) is not linked to your Github account, which means this PR won't count as your contribution in https://github.com/OpenAPITools/openapi-generator/graphs/contributors.

Let me know if you need help fixing it.

Ref: https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-can-i-update-commits-that-are-not-linked-to-my-github-account

[loic-seguin]

Thanks for the PR but your commit (as shown in the Commits tab) is not linked to your Github account, which means this PR won't count as your contribution in https://github.com/OpenAPITools/openapi-generator/graphs/contributors.

Let me know if you need help fixing it.

Ref: https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-can-i-update-commits-that-are-not-linked-to-my-github-account

done