fix(pytorch): add missing f-string prefixes to error messages

[andrewwhitecdw]

Fix two error messages that print literal placeholders instead of the intended values.

• In QuantizedTensor.__torch_dispatch__, the placeholder {cls.__name__} was not interpolated because the string was missing the f prefix. Users calling .view() on a quantized tensor would see the literal text instead of the class name.

• In NVFP4Tensor.__torch_dispatch__, the placeholder {len(args)} was not interpolated for the same reason, making the arg-count diagnostic misleading.

Both fixes are one-character additions of the missing f prefix, restoring the intended error diagnostics.

[greptile-apps]

Greptile Summary

This PR fixes two error messages that were printing literal placeholder text instead of interpolated values due to missing f prefixes on string literals.

• In QuantizedTensor.__torch_dispatch__, adds f prefix so {cls.__name__} resolves to the actual subclass name in the NotImplementedError raised on .view() calls.
• In NVFP4Tensor.__torch_dispatch__, adds f prefix so {len(args)} resolves to the actual argument count in the RuntimeError raised when an unexpected number of arguments is passed to the view op; the string is also lightly reformatted across two lines.

Confidence Score: 5/5

Both changes are minimal, isolated one-character (plus reformatting) fixes to error message strings with no impact on control flow or data handling.

The only changes are adding f prefixes to two string literals inside raise statements. No logic, no data paths, and no APIs are modified — only the text of exception messages is corrected.

Files Needing Attention: No files require special attention.

Important Files Changed

Filename	Overview
transformer_engine/pytorch/quantized_tensor.py	Added missing f prefix to the NotImplementedError string in QuantizedTensor.__torch_dispatch__ so {cls.__name__} is interpolated correctly.
transformer_engine/pytorch/tensor/nvfp4_tensor.py	Added missing f prefix to the RuntimeError string in NVFP4Tensor.__torch_dispatch__ so {len(args)} is interpolated correctly; also reformatted the string to a two-line form for readability.

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