Migrate tests/test_gpu_aamp.py to npt.assert_allclose

[viknesh-ai]

Related to #1175

Covers tests/test_gpu_aamp.py (34 call sites, this file's tests only actually run under CUDA — locally it's a single module-level skip, so I verified with NUMBA_ENABLE_CUDASIM=1 instead). Renamed comp_mp to cmp_mp, flipped every call to (cmp, ref) order.

Same object-dtype situation as test_aamp.py: naive.aamp(...) mixes a float distance column with an int index column, so full-array and [:, 0]-sliced comparisons both needed a float64 cast. A few call sites use decimal=config.STUMPY_TEST_PRECISION — kept those as a config reference rather than the 1.5e-07 literal. Several pd.Series variants are commented out in the original file; updated their syntax too but left them commented.

37/37 passing under CUDA simulation (matches how test.sh coverage actually exercises this file).

To Do List

• assert_almost_equal -> assert_allclose
• no rtol=0
• actual, desired order
• atol=1.5e-07 literal where no decimal= was set; config.STUMPY_TEST_PRECISION reference kept where it was
• cmp not comp
• ref_/cmp_ naming, .astype(np.float64) cast where the source is dtype=object

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[gitnotebooks]

Review these changes at https://app.gitnotebooks.com/stumpy-dev/stumpy/pull/1190

[viknesh-ai]

@seanlaw next file in the split — same conventions as the previous PRs. Ready for review whenever you have time.