fix(i18n): translate "nodes.note.addNote" as "メモを追加" in ja-JP

[t-daisuke]

"Note" is more accurately translated as "メモ" rather than "コメント" in Japanese. The note feature is for personal memos/annotations on workflow nodes, not comments directed at others. This aligns with common Japanese UI conventions (e.g., macOS Notes app is "メモ").

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Summary

Fix Japanese translation of nodes.note.addNote from "コメントを追加" (Add Comment) to "メモを追加" (Add Note).

"Note" should be translated as "メモ" rather than "コメント" in Japanese. The note feature is for personal　memos/annotations on workflow nodes, not comments directed at others. This
aligns with common Japanese UI conventions (e.g., macOS Notes app is "メモ").

Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran make lint and make type-check (backend) and cd web && npx lint-staged (frontend) to appease the lint gods