Allow NaN and infinite values for float attributes

[lisa0314]

This issue was raised in this CL review- https://chromium-review.googlesource.com/c/chromium/src/+/6081404/5..10/third_party/blink/web_tests/external/wpt/webnn/validation_tests/elu.https.any.js#b50.

The current blink IDL uses float alpha while spec defines as double alpha. I suppose both have issues and it should be defined as unrestricted double which supports both infinite and NaN.

[inexorabletash]

See here and here for past discussion. We settled on not adding unrestricted since we didn't think there were use cases for allowing this class inputs to include infinities and NaNs, and that early error for developers was better.

https://g-issues.chromium.org/issues/382108345 doesn't provide use cases either, it's just pointing out where the impl doesn't match the spec.

Are there use cases, e.g. existing models where ORT Web would generate e.g. elu() calls with Infinities or NaNs? If so, happy to revisit!