Fixes # .

Summary/Motivation:

This resolves a problem with the implementation of PyNumero's BlockVector: numpy has the convention that __getitem__(tuple()) will return the original array. This adds support for that convention in BlockVector so that NumPy2 implementations of operators like isclose will not fail.

Changes proposed in this PR:

• Adopt NumPy convention that passing an empty tuple to __getitem__ will return the original array.

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