fix: removing prompt from text output in outlines serve

[Martins6]

PR to solve #1525 .

[Martins6]

It says that the tests are failing but I don't see how they are connected at all. It seems it is a bug?

This is the function failing:

@pytest.mark.parametrize("pattern", REGEX_PATTERNS)
@pytest.mark.parametrize("model_fixture", ALL_MODEL_FIXTURES)
def test_generate_regex(request, model_fixture, pattern):
    model = request.getfixturevalue(model_fixture)
    generator = generate.regex(model, pattern)
    res = generator(**get_inputs(model_fixture), max_tokens=20)
    assert re.fullmatch(pattern, res) is not None, res

I don't see how they are connected to serve module or serve main function. So...I'm not sure what to do next 😅

cc: @rlouf @cpfiffer