[Feature]: Suppress changelog if not tagged

[Malcolmnixon]

Problem Statement

The Build Notes should only include the changelog if the from and to versions are actual git-tags in the repository.

Proposed Solution

The GitHubRepoConnector.GetBuildInformationAsync method should suppress generating the changelog link unless both the from and to versions are in branchTagNames.

This should be tested by unit testing, but doesn't need any new requirements.

Alternatives Considered

No response

Usage Examples

Benefits

Suppressing bogus changelog links for simple main-branch or PR builds.

Priority

Medium - Would improve my workflow

Willingness to Contribute

Yes, I can submit a pull request

Additional Context

No response

Checklist

• I have searched existing issues to ensure this is not a duplicate
• I have provided a clear description of the feature
• I have explained why this feature would be useful