[ja] add translation of content/en/blog/2024/spring-starter-stable/index.md

[ymotongpoo]

Summary

Translates content/en/blog/2024/spring-starter-stable/index.md into Japanese as content/ja/blog/2024/spring-starter-stable/index.md.

Checks

• I have read and followed the Contributing docs, especially the "First-time contributing?" section.
• This PR has content that I did not fully write myself.
  • I used AI and I have read and followed the Generative AI Contribution Policy.
• I have the experience and knowledge necessary to understand, review, and validate all content in this PR.¹

Preview

• Japanese (this PR): https://deploy-preview-10394--opentelemetry.netlify.app/ja/blog/2024/spring-starter-stable/
• English (canonical): https://opentelemetry.io/blog/2024/spring-starter-stable/

Footnotes

1. Yes, I can answer maintainer questions about the content of this PR, without using AI. ↩