fix(comments): load comments styles when the comments app is loaded

[susnux]

• Resolves: refactor(comments): migrate to Vue 3 #58353 (comment)

Summary

We also need to load the styles not only the scripts of the comments app.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI

[susnux]

/backport to stable34

[edward-ly]

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