chore: remove support for .uccignore

[hetangmodi-crest]

Issue number:
ADDON-76463

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

Support for .uccignore has been removed. If a user includes this file, the build will now fail with an error message.

User experience

Users will no longer be able to use .uccignore feature.

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

[github-actions]

Code Coverage 🎉

Type	PR	Develop	Change	Status
Line Coverage	88.75%	88.26%	0.49%	🟢 Increased
Branch Coverage	82.87%	81.93%	0.94%	🟢 Increased

[sgoral-splunk]

Do we want to include this in the next major version?