Fix type hint for image reader

[Kirscher]

Description

This PR fixes the type hint for image reader to correctly handle Cupy arrays and removes the TODO.

Types of changes

• [x] Non-breaking change (fix or new feature that would not break existing functionality).

[coderabbitai[bot]]

Walkthrough

The change adds a NdarrayOrCupy type alias in monai/data/image_reader.py (defined under a TYPE_CHECKING block to reference cupy.ndarray when available, falling back otherwise) and imports Union. Type annotations for internal image data containers are updated from list[np.ndarray] to list[NdarrayOrCupy] in the relevant get_data implementations. No runtime logic is changed; this is a static typing update to allow NumPy or CuPy arrays.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

• Homogeneous, localized annotation changes in a single file
• Verify TYPE_CHECKING block and alias resolve correctly and do not introduce runtime dependency
• Confirm Union import and any added typing imports are used and lint-clean

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: updating type hints in the image reader to support CuPy arrays.
Description check	✅ Passed	Description covers the change objective and marks it as non-breaking, but lacks detail about the specific implementation and omits testing sections.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing touches

• [ ] 📝 Generate docstrings

🧪 Generate unit tests (beta)

• [ ] Create PR with unit tests
• [ ] Post copyable unit tests in a comment

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📥 Commits

Reviewing files that changed from the base of the PR and between e242c44aacde722a070773bc5633bbffe35bfa87 and 1a58715442f3a7b1e3ea86271bec7e61d7691c67.

📒 Files selected for processing (1)

• monai/data/image_reader.py (4 hunks)

🚧 Files skipped from review as they are similar to previous changes (1)

• monai/data/image_reader.py

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[KumoLiu]

/build

[ericspod]

Hi @KumoLiu The packaging test is failing when running out of space, is this possibly related to #7901? I remember this was solved with the fix where we clean out some things in the image being used.