[bug] Fix handling of temperature argument

[CalebCourier]

Describe the bug
The defaulting of the temperature param yields the below error:

litellm.UnsupportedParamsError: gpt-5 models (including gpt-5-codex) don't support temperature=0. Only temperature=1 is supported. To drop unsupported params set litellm.drop_params = True

To Reproduce
Use any gpt-5 model like below:

from guardrails import Guard

guard = Guard()

res = guard(
    model="gpt-5-nano",
    messages=[{
        "role": "user",
        "content": "Hello, world!"
    }]
)

print(res)

Expected behavior
Users should be able to use gpt-5-* models without explicitly setting temperature to 1

Library version:
Version (e.g. 0.1.5)
0.6.7

[ram-from-tvl]

Hi @CalebCourier
i would like to work on this Issue..?
Thank you!

[CalebCourier]

Thanks again @ram-from-tvl! I think the test suite for this looks like a set of integration tests that use models from gpt 3, 4, and 5 with and without temperature set explicitly.