[testing] Fix Infleqtion tests for state prep

[khalatepradnya]

• Follow-up to PR Reenable state support for remote REST QPU platforms #3824
• Fix the assert_close function.
• Manually tested

python3 -m pytest -v python/tests/backends/test_Infleqtion.py
=================================================================== test session starts ===================================================================
platform linux -- Python 3.12.3, pytest-8.3.0, pluggy-1.6.0 -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /workspaces/cuda-quantum
configfile: pyproject.toml
plugins: anyio-4.13.0, xdist-3.8.0
collected 9 items                                                                                                                                         

python/tests/backends/test_Infleqtion.py::test_simple_kernel PASSED                                                                                 [ 11%]
python/tests/backends/test_Infleqtion.py::test_all_gates PASSED                                                                                     [ 22%]
python/tests/backends/test_Infleqtion.py::test_multiple_qvector PASSED                                                                              [ 33%]
python/tests/backends/test_Infleqtion.py::test_multiple_measure PASSED                                                                              [ 44%]
python/tests/backends/test_Infleqtion.py::test_observe PASSED                                                                                       [ 55%]
python/tests/backends/test_Infleqtion.py::test_state_synthesis PASSED                                                                               [ 66%]
python/tests/backends/test_Infleqtion.py::test_state_preparation PASSED                                                                             [ 77%]
python/tests/backends/test_Infleqtion.py::test_state_preparation_builder PASSED                                                                     [ 88%]
python/tests/backends/test_Infleqtion.py::test_exp_pauli PASSED                                                                                     [100%]

=================================================================== 9 passed in 18.45s ====================================================================

[github-actions]

CUDA Quantum Docs Bot: A preview of the documentation can be found here.

[github-actions]

CUDA Quantum Docs Bot: A preview of the documentation can be found here.

[github-actions]

CUDA Quantum Docs Bot: A preview of the documentation can be found here.

[sacpis]

Overall LGTM. Thanks @khalatepradnya. Left a few comments.

[1tnguyen]

👍