fix(frontend): テーマプレビューが見れない問題を修正

[nullnyat]

What

テーマプレビューが見れるようになる。

Why

テーマプレビューが見れなかった　#12533

Additional info (optional)

Checklist

• Read the contribution guide
• Test working in a local environment
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.90%. Comparing base (1c5d0cf) to head (14b8ef3).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop   #14097   +/-   ##
========================================
  Coverage    77.90%   77.90%           
========================================
  Files          185      185           
  Lines        25562    25562           
  Branches       487      487           
========================================
  Hits         19915    19915           
  Misses        5640     5640           
  Partials         7        7           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[syuilo]

🙏🏻

[samunohito]

@nullnyat
差し支えなければ、CHANGELOG.md更新も別プルリクで上げていただけると助かります… 🙏