fix: obfuscated the value of JWT

[lafirest]

Fixes EMQX-10242

Summary

🤖 Generated by Copilot at ba2e057

Added jwt as a sensitive key to is_sensitive_key function in emqx_utils.erl. This helps to mask sensitive information in logs and configs.

PR Checklist

Please convert it to a draft if any of the following conditions are not met. Reviewers may skip over until all the items are checked:

• Added tests for the changes
• Changed lines covered in coverage report
• Change log has been added to changes/{ce,ee}/(feat|perf|fix)-<PR-id>.en.md files
• For internal contributor: there is a jira ticket to track this change
• If there should be document changes, a PR to emqx-docs.git is sent, or a jira ticket is created to follow up
• Schema changes are backward compatible

Checklist for CI (.github/workflows) changes

• If changed package build workflow, pass this action (manual trigger)
• Change log has been added to changes/ dir for user-facing artifacts update

[yanzhiemq]

Enhancements

• Improved log security for JWT, now it will be obfuscated before print.

[yanzhiemq]

增强

• 改进了JWT 的日志安全性，现在在打印之前将进行模糊化处理。