Bug fix: wrong output bands

[jiang-yuha0]

• Output the band_structure from wannier90_optimal correctly:
  In Avoid unnecessary errors when launching Wannier90OptimizeWorkChain … #40, the bands_plot has been separated from the wannier_plot and integrated into each wannier90_optimize_iteration.
  Because wannier_plot cannot be found, the original results logic in Wannier90OptimizeWorkChain will directly output the interpolated_bands from wannier90 as the final output bands rather than from the wannier90_optimal.

[aiida-cla-bot]

All contributors have accepted the CLA ✅

---

_{You might need to click the "Update/Rebase branch" button to update the pull request and rerun the GitHub actions to pass the CLA check.
Posted by the CLA Assistant Lite bot.}