Update tox.ini && conf.py file

[otcbot]

Performed-by: gitea/infra/otc-metadata/tools/generate_doc_confpy.py

[otc-zuul[bot]]

Build failed. https://zuul.otc-service.com/t/eco/buildset/6b7290be4c4c410d840ae42fb0c68755

:heavy_check_mark: build-otc-api-ref SUCCESS in 12m 40s :heavy_check_mark: build-otc-umn SUCCESS in 12m 52s :heavy_check_mark: noop SUCCESS in 0s :x: otc-tox-docs RETRY_LIMIT in 1m 54s

[vladimirhasko]

regate

[otc-zuul[bot]]

Build succeeded. https://zuul.otc-service.com/t/eco/buildset/0e794c56da4d493cb610731f5a0e600f

:heavy_check_mark: build-otc-api-ref SUCCESS in 3m 50s :heavy_check_mark: build-otc-umn SUCCESS in 3m 38s :heavy_check_mark: noop SUCCESS in 0s :heavy_check_mark: otc-tox-docs SUCCESS in 11m 25s