chore(cache): change cache enabled message to debug log

[chenjiahan]

Summary

Updated the log level to debug for the message indicating that Rspack persistent cache is enabled, since the Rspack persistent cache is now more stable.

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[netlify]

✅ Deploy Preview for rsbuild ready!

Name	Link
🔨 Latest commit	66a5e42
🔍 Latest deploy log	https://app.netlify.com/projects/rsbuild/deploys/68709878bc333c00084862f1
😎 Deploy Preview	https://deploy-preview-5580--rsbuild.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
Lighthouse	1 paths audited Performance: 74 (no change from production) Accessibility: 97 (no change from production) Best Practices: 100 (no change from production) SEO: 100 (no change from production) PWA: 60 (no change from production) View the detailed breakdown and full score reports

---

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

[Copilot]

Pull Request Overview

Adjusts logging for the Rspack persistent cache message by lowering its level to debug and removing the “experimental” label, and cleans up related imports.

• Removed color import since it’s no longer used.
• Changed the cache-enabled message from logger.info to logger.debug and dropped the experimental suffix.

Comments suppressed due to low confidence (2)

packages/core/src/plugins/cache.ts:181

• Add or update tests to ensure the log level change from info to debug and removal of the experimental label for the Rspack persistent cache.

        logger.debug('Rspack persistent cache enabled');

packages/core/src/plugins/cache.ts:180

• Consider updating documentation comments or external docs to reflect that Rspack persistent cache is now considered stable and no longer experimental.

      if (cacheEnabled && api.context.bundlerType === 'rspack') {