Fix test: integration_tests/reference_frame_test.py:test_sun_ememe

[carise]

integration_tests/reference_frame_test.py:test_sun_ememe is currently failing.

The test appears to test a propagation that's sun-centered in EMEME2000 reference frame, and expects end state to be in ICRF.

From the test:

        # The output state is expected to be in ICRF.
        expected_end_state = [73978163.61069362, -121822760.05571477, -52811158.83249758,
                              31.71000343989318, 29.9657246374751, .6754531613947713]
        # These values are in EMEME. The resulting ephemeris is not expected to match these values.
        # expected_end_state = [73978158.47632701, -132777272.5255892, 5015.073123970032,
        #                       31.710003506237434, 27.761693311026138, -11.299967713192564]

The actual end state is the commented-out expected_end_state and is in EMEME. I'm not sure when this test was last working. I also ran the propagation parameters/OPM parameters through single_run_demo and got the same expected_end_state (the EMEME one).