[Bug]: Python float attributes not valid against float64 spec

[rly]

What happened?

Zarr attributes fail to validate against an attribute spec with dtype=float64. This is because Zarr reads the attributes (in .zattrs, a JSON file), as Python-native float, and the HDMF validator reads float values as dtype="float" which in HDMF aliases to float32. This is incorrect because Python-native floats are 64-bit.

Similarly, Python-native int has unlimited precision and so should be aliased to int64, not int32.

NWBHDF5IO/h5py reads scalars as numpy objects with numpy dtypes so this is not an issue there.

I believe this issue would also come up when validating in-memory, unwritten files.

This is blocking validation of some Allen Institute zarr files that have an extension with an attribute with float64 dtype.

Steps to Reproduce

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Traceback

Operating System

Windows

Python Version

3.13

Package Versions

No response