chore: fix inverted index japanese translation

[os1ma]

Checklist:

Important

Please review the checklist below before submitting your pull request.

• Please open an issue before creating a PR or link to an existing issue

No. Because this PR is very small.

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods

Description

Updated Japanese translation of "Inverted Index" to the more commonly used term "転置インデックス" instead of "逆インデックス".

Example: https://ja.wikipedia.org/wiki/%E8%BB%A2%E7%BD%AE%E3%82%A4%E3%83%B3%E3%83%87%E3%83%83%E3%82%AF%E3%82%B9

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update, included: Dify Document
• Improvement, including but not limited to code refactoring, performance optimization, and UI/UX improvement
• Dependency upgrade

Testing Instructions

I have launched the application and verified its display following the procedures described in https://github.com/langgenius/dify/blob/main/CONTRIBUTING.md.