Translating `en/internal` folder docs to Japanese 🇯🇵 (#26747)
* Add translation to fitst 3 file of internal folder
* Update Toctree.md and add files
* Update docs/source/ja/internal/generation_utils
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
* Rename generation_utils file
* rename pipelines_utils.md
* Change file names
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Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>