Update emby to version 4.9.1

[al-lac]

🤖 This is an automated pull request to update emby to version 4.9.1. This PR must be reviewed and tested before merging.

Auto-generated update considerations:

• Database performance improvements may require reindexing or optimization
• Upgrade to .NET 8 could require updating runtime dependencies
• New maintenance mode feature may affect availability during upgrades
• Changes to environment variables for remote quality settings (split into two)
• New WebStreams plugin may require additional configuration
• New options for limiting transcoding resolution could affect performance and quality
• Changes to library scanning behavior for multi-part and multi-version detection
• New database integrity checks before backups may increase backup time
• Potential changes to hardware detection timing may affect playback on startup
• Adjustments to realtime monitor delay could impact scanning behavior
• Changes to collections library and content visibility in new libraries
• Modifications to Live TV views and series recording options
• Addition of new library settings and reordering options may require review

Original GitHub release notes

[al-lac]

🤖 This is an automated summary of installation tests for emby:

• ✅ App successfully installed in umbrel-dev instance
• ✅ App successfully listed in umbrel.yaml
• ✅ App UI successfully returns a 200 status code
• 📸 Screenshot of the app:
  

This PR must still be reviewed and tested before merging.

[github-actions]

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