Remove in-place modification of shape attribute for numpy.ndarray

[antonwolfy]

NumPy 2.5 is going to deprecate in-place assignment to ndarray.shape.

Previously _as_zero_dim_ndarray in dpnp.tensor relied on this pattern (view.shape = tuple()) to turn a size-1 host buffer into a 0-dim array before extracting a Python scalar.

This PR replaces it with reshape(()), which is the recommended non-deprecated alternative and returns a true
0-dim array.

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[github-actions]

View rendered docs @ https://intelpython.github.io/dpnp/pull/2958/index.html

[coveralls]

coverage: 78.091%. remained the same — remove-in-place-modification-for-numpy.ndarray.shape into master

[github-actions]

Array API standard conformance tests for dpnp=0.21.0dev1=py313h509198e_15 ran successfully.
Passed: 1357
Failed: 3
Skipped: 16