IDE should ignore board options with missing label

[cmaglie]

Describe the problem

It may happen when a platform does not specify the menu label for all the options in the menu:

To reproduce

1. Use the nightly build of the CLI or a build with this patch included: Do not treat custom menu options without label as 'malformed' arduino-cli#1882
2. Install the platform m5stack:
   • URL: https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/arduino/package_m5stack_index.json
   • Version: m5stack:esp32 2.0.4
3. Select the board "M5Stack-Station"
4. The "Tools" menu has an empty item as showed in the image above

Expected behavior

The empty Tools menu item must be ignored.

Arduino IDE version

nightly

Operating system

N/A

Operating system version

Additional context

No response

Issue checklist

• I searched for previous reports in the issue tracker
• I verified the problem still occurs when using the latest nightly build
• My report contains all necessary details