fix tracing=False no longer working

[Butanium]

fixes #308

[Butanium]

Btw no idea what you're doing with this custom backend, but this test

nnsight/tests/test_tiny.py

Line 43 in 7664e72

with tiny_model.trace(tiny_input):

won't work in 0.4 as it uses .value but somehow works due to the custom backend.
Therefore I'm unsure how to write a test for this tracing=False behavior

[JadenFiotto-Kaufman]

@Butanium Can you just add a check like:

if isinstance(output, Proxy):
    output = output.value

Theres an option to turn off the automatic value injection (or with different backends), so if thats off id like this to still return the real value. After that ill merge it in thanks!!

[Butanium]

done!