test: add maybe_xfail for quantized micro static batch logprobs checks

[tjohnson31415]

Description

We are seeing test failures in CI from logprobs differences with the ibm-granite/granite-3.3-8b-instruct-FP8 model. This happens somewhat randomly... so this PR will convert these failures into xfail while still having the tests execute.

[github-actions]

👋 Hi! Thank you for contributing to vLLM support on Spyre.
Just a reminder: Make sure that your code passes all the linting checks, otherwise your PR won't be able to be merged. To do so, first install the linting requirements, then run format.sh and commit the changes. This can be done with uv directly:

uv sync --frozen --group lint --active --inexact

Or this can be done with pip:

uv pip compile --group lint > requirements-lint.txt
pip install -r requirements-lint.txt
bash format.sh

Now you are good to go 🚀