StandardNodule : Remove deprecated setCompatibleLabelsVisible()

[ericmehl]

This was deprecated in #6135. We don't expect there to be any other uses of it, and the fix to avoid the deprecated method is pretty simple, so it should be safe to remove.

Checklist

• I have read the contribution guidelines.
• I have updated the documentation, if applicable.
• I have tested my change(s) in the test suite, and added new test cases where necessary.
• My code follows the Gaffer project's prevailing coding style and conventions.