[Hotfix Main]: [HOTFIX] New example file: dtu wind turbine

[github-actions]

Hotfix of PR #1865 (#1865) to the main branch.
Hey @marcvivesmassana, please review this hotfix PR created from your original PR.

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Note

Low Risk
Adds a new example entry with a single external geometry download URL and exports it from flow360.examples; minimal surface area change and no core solver logic touched.

Overview
Adds a new DTU_WindTurbine example (subclassing BaseTestCase) that points to a publicly hosted DTU 10MW geometry EGADS file.

Updates flow360/examples/__init__.py to import and expose DTU_WindTurbine via __all__ so it’s available through the flow360.examples package.

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