[ja] Translate docs/concepts/security/service-accounts.md into Japanese

[kohbis]

/language ja

Description

Translate docs/concepts/security/service-accounts.md into Japanese.

Issue

Closes: #47546

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign bells17 for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• content/ja/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[netlify]

✅ Pull request preview available for checking

Built without sensitive environment variables

Name	Link
🔨 Latest commit	eda6673
🔍 Latest deploy log	https://app.netlify.com/sites/kubernetes-io-main-staging/deploys/67386916b0c6920008ea832b
😎 Deploy Preview	https://deploy-preview-48719--kubernetes-io-main-staging.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[Okabe-Junya]

ありがとうございます、何点かコメントさせていただいたので、適宜ご確認ください

Deploy preview: https://deploy-preview-48719--kubernetes-io-main-staging.netlify.app/ja/docs/concepts/security/service-accounts/

/label tide/merge-method-squash