Add esp-alloc to trouble ble example

[okhsunrog]

Thank you for your contribution!

We appreciate the time and effort you've put into this pull request.
To help us review it efficiently, please ensure you've gone through the following checklist:

Submission Checklist 📝

• [+ ] I have updated existing examples or added new ones (if applicable).
• [+ ] I have used cargo xtask fmt-packages command to ensure that all changed code is formatted correctly.
• My changes were added to the CHANGELOG.md in the proper section.
• I have added necessary changes to user code to the Migration Guide.
• [+ ] My changes are in accordance to the esp-rs API guidelines

Extra:

• [+ ] I have read the CONTRIBUTING.md guide and followed its instructions.

Pull Request Details 📖

After #2099 we need to explicitly setup heap for esp-wifi crate. The wifi_embassy_ble.rs example was updated, but the wifi_embassy_trouble.rs, which was introduces by another PR in the same day isn't updated yet. This small PR fixes the example so it's consistent with the other esp-wifi examples.

[MabezDev]

Oops, good catch, thanks!

[bjoernQ]

Thanks!