Remove unused getResidualKey local variable.

[richersoon]

Issue reference

[Reference or link to the issue covered in the PR]

No specific issue referenced. This is part of ongoing code quality improvement.

Documentation PR reference

No documentation update is needed for this change as it’s an internal code refactor.

Documentation project

Description and context

This change removes an unused local variable in the getResidualKeys method, which was identified as a code smell. The variable subscriber was defined but never utilized in the method, contributing unnecessary clutter. Removing it enhances code readability and maintainability.

Benefits

Cleaner and more maintainable code.

Slight performance improvement by avoiding unnecessary object creation.

Reduces potential confusion for future maintainers or developers.

Possible Drawbacks

No significant drawbacks are expected as this change does not alter any logic or behavior of the application.

Checklist

• Unit tests provided (not applicable for this refactor)
• Integration tests provided (not applicable for this refactor)
• [] Documentation updated in documentation project (not needed for this change)
• Updated example in example projects (not needed for this change)