Adding Japanese translations for UI (i18n)

[rsanda]

This PR contains the translations for Japanese as proposed in the following mail.
https://lists.apache.org/thread/wdys3tnfx7vnhv350bwcbcmoc52h3yyd

This is the first time I'm contributing to Airflow. So, if I am doing something wrong, please feel free to point it out. 😅
Looking forward to hearing your feedback!

Best,

---

^ Add meaningful description above
Read the Pull Request Guidelines for more information.
In case of fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
In case of a new dependency, check compliance with the ASF 3rd Party License Policy.
In case of backwards incompatible changes please leave a note in a newsfragment file, named {pr_number}.significant.rst or {issue_number}.significant.rst, in airflow-core/newsfragments.

[boring-cyborg]

Congratulations on your first Pull Request and welcome to the Apache Airflow community! If you have any issues or are unsure about any anything please check our Contributors' Guide (https://github.com/apache/airflow/blob/main/contributing-docs/README.rst)
Here are some useful points:

• Pay attention to the quality of your code (ruff, mypy and type annotations). Our prek-hooks will help you with that.
• In case of a new feature add useful documentation (in docstrings or in docs/ directory). Adding a new operator? Check this short guide Consider adding an example DAG that shows how users should use it.
• Consider using Breeze environment for testing locally, it's a heavy docker but it ships with a working Airflow and a lot of integrations.
• Be patient and persistent. It might take some time to get a review or get the final approval from Committers.
• Please follow ASF Code of Conduct for all communication including (but not limited to) comments on Pull Requests, Mailing list and Slack.
• Be sure to read the Airflow Coding style.
• Always keep your Pull Requests rebased, otherwise your build might fail due to changes not related to your commits.
  Apache Airflow is a community-driven project and together we are making it better 🚀.
  In case of doubts contact the developers at:
  Mailing List: dev@airflow.apache.org
  Slack: https://s.apache.org/airflow-slack

[potiuk]

Wooohoooe

[potiuk]

Technical approval - but would be great for people who speak Japanese to review: @sekikn Maybe :)

[choo121600]

WOW, it’s great to see a neighboring country language being added🙌

---

You can add and remove keys using a command like this 😉
breeze ui check-translation-completeness --language ja --add-missing --remove-extra

[jscheffl]

Besides the small gaps looks very good. But to further maintain we should also adjust the .github/CODEOWNERS and describe who would be sponsor as committer and who would be engaged translator. Can you add this? Would you volunteer yourself to be the engaged translator?

残念ながら日本語は話せませんが、Google翻訳を使って翻訳を試しています。小さな欠落を除けば、非常に良さそうです。しかし、さらにメンテナンスを行うためには、.github/CODEOWNERS を編集し、誰がコミッターとしてスポンサーとなり、誰が翻訳者として関与するかを記載する必要があります。この情報を追加していただけますか？ご自身で翻訳者として関与していただけますか？

[sekikn]

Thank you for the review and advice everyone! Regarding .github/CODEOWNERS, @uranusjr, @rsanda, and I will be involved as the translation sponsor, engaged translator, and translation owner respectively. Would you address the comments above @rsanda?

[rsanda]

Thank you all.
Will add the responsible persons to the file and ping you all.

Thanks again.

[pierrejeambrun]

We also need to update the CODEOWNERS file. (translation owners + sponsors)

Code looks good.

Can't vouch for the translation

[rsanda]

Thanks a lot for the feedback.
I have updated the code with all the comments.

• Added codeowners
• Removed extra translations and added missing ones as breeze result suggested
• Didn't translate "Providers" in "ja/admin.json" following the example of other languages.

[choo121600]

Gooood 🙌

[potiuk]

All important tests passed :). Merging. Congrats on 100% completion of Japanese :D WOOOHOOO!!!! 🗾

[potiuk]

The failing tests is fixed in main already.

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.

[github-actions]

Backport failed to create: v3-1-test. View the failure log Run details

Status	Branch	Result
❌	v3-1-test

You can attempt to backport this manually by running:

cherry_picker 93454f0 v3-1-test

This should apply the commit to the v3-1-test branch and leave the commit in conflict state marking
the files that need manual conflict resolution.

After you have resolved the conflicts, you can continue the backport process by running:

cherry_picker --continue

[potiuk]

No backporting needed .

[potiuk]

Just to Add - No backporting needed - unless you would like to contribute it to v3-1-test -> some small changes will be needed as set of features is abit different in v3-1-test @rsanda . You could open a new pr wiht those changes towards v3-1-test and submit it there - I do not think anyone will have anythoing against adding Japanese in 3.1.6