fix: include built UI files in the wheel package

[kkedziak-splunk]

Issue number: ADDON-83800

PR Type

What kind of change does this PR introduce?

• Feature
• Bug Fix
• Refactoring (no functional or API changes)
• Documentation Update
• Maintenance (dependency updates, CI, etc.)

Summary

Changes

Poetry changed the format of pyproject.toml, related to included files.

Our existing configuration resulted in inclusion of files only in the sdist package, not in the wheel.

This resulted in no UI files in the UCC wheel package.

User experience

It makes UCC usable.

Checklist

If an item doesn't apply to your changes, leave it unchecked.

Review

• self-review - I have performed a self-review of this change according to the development guidelines
• Changes are documented. The documentation is understandable, examples work (more info)
• PR title and description follows the contributing principles
• meeting - I have scheduled a meeting or recorded a demo to explain these changes (if there is a video, put a link below and in the ticket)

Tests

See the testing doc.

• Unit - tests have been added/modified to cover the changes
• Smoke - tests have been added/modified to cover the changes
• UI - tests have been added/modified to cover the changes
• coverage - I have checked the code coverage of my changes (see more)

Demo/meeting:

Reviewers are encouraged to request meetings or demos if any part of the change is unclear