fix zarr.open (v3) lacks context manager

[LucaMarconato]

zarr-python v3 removed the context manager functionalities from zarr.open (zarr-developers/zarr-python#2619). This small PR adds a workaround for that.

[Copilot]

Pull Request Overview

This PR addresses the removal of context manager functionality from zarr.open in zarr-python v3 by implementing a workaround that provides the missing context manager behavior.

• Implements a custom zarr_open context manager function to replace direct zarr.open usage
• Updates all instances of zarr.open context manager usage to use the new workaround function
• Ensures proper cleanup of zarr stores when exiting the context

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/spatialdata_io/_utils.py	Adds zarr_open context manager workaround function with proper store cleanup
src/spatialdata_io/readers/xenium.py	Updates zarr.open usage to use the new zarr_open context manager

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[Copilot]

Calling f.store.close() may fail if the store doesn't have a close() method or if f.store is None. Consider adding a check to ensure the store exists and has a close method before calling it, or wrap in a try-except block to handle potential AttributeError.

Suggested change

	f.store.close()
	if f.store is not None and hasattr(f.store, "close"):
	f.store.close()