[BUG] flaky incumbent callback tests with swath1

[mlubin]

These tests are frequently failing, e.g., https://github.com/NVIDIA/cuopt/actions/runs/25745323385/job/75606881948#step:12:1804

The task is to fix the underlying issue and re-enable the tests that were disabled in #1208.

[nguidotti]

The same crash was also documented here: #1185

[mlubin]

@nguidotti thanks for the reference, closing this one as a duplicate