Fix preview latent on AMD Devices for Windows.

[traugdor]

Improve Latent Preview by forcing dtype=uint8
Check if device supports non-blocking

[traugdor]

Closes #3539

[dnswd]

Does the uint8 casting still needed after changes on device_supports_non_blocking?

[traugdor]

Does the uint8 casting still needed after changes on device_supports_non_blocking?

It seems so. I was still running into issues without it, but if you can provide evidence that it's not needed on some AMD devices, then it may be worth revisiting in the future.

[traugdor]

Closing in favor of commits to main repo that have addressed this issue.

[traugdor]

I am reopening this pull request because after updating ComfyUI, I am still getting this error in the latent_preview.py file:

TypeError: Cannot handle this data type: (1, 1, 3), <f4

While my code (as is) is outdated with the recent updates, uint8 needs to be enforced, especially on AMD devices or this will continue to break.

[mcmonkey4eva]

If this remains an issue, please repush the change to resolve the merge conflict