Update zigbee2mqtt to version 2.9.1

[al-lac]

🤖 This is an automated pull request to update zigbee2mqtt to version 2.9.1. This PR must be reviewed and tested before merging.

Auto-generated update considerations:

• The OTA functionality has been completely re-implemented in 2.8.0, which modifies the logging format during OTA updates; existing automations or log parsers that rely on OTA log output may need to be updated.
• Users can now upload custom OTA files directly through the frontend in 2.8.0; no additional container or volume changes are noted, but the OTA file storage path should be verified to ensure it is accessible within the Docker volume.
• A re-configure mechanism via definition.version was introduced in 2.9.0, which may trigger automatic re-configuration of some devices on first startup after upgrade.
• 2.9.1 is a hotfix release addressing a broken onboarding flow introduced in 2.9.0; upgrading directly to 2.9.1 is recommended to avoid the onboarding issue.
• No environment variable changes, database migration steps, or added/removed containers were identified across these releases.

Original GitHub release notes

[al-lac]

🤖 This is an automated summary of installation tests for zigbee2mqtt:

• ✅ 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]

🎉   Linting finished with no errors or warnings   🎉

Thank you for your submission! This is an automated linter that checks for common issues in pull requests to the Umbrel App Store.

Please review the linting results below and make any necessary changes to your submission.

Linting Results

Severity	File	Description
ℹ️	zigbee2mqtt/docker-compose.yml	Potentially using unsafe user in service "app": The default container user "root" can lead to security vulnerabilities. If you are using the root user, please try to specify a different user (e.g. "1000:1000") in the compose file or try to set the UID/PUID and GID/PGID environment variables to 1000.

Legend

Symbol	Description
❌	Error: This must be resolved before this PR can be merged.
⚠️	Warning: This is highly encouraged to be resolved, but is not strictly mandatory.
ℹ️	Info: This is just for your information.

[al-lac]

Tested update on Umbrel dev instance.