Failing test with the GMT 6.5.0

```
__________________ test_earth_relief_03s_default_registration __________________

def test_earth_relief_03s_default_registration():
"""
Test that the grid returned by default for the 3 arc-second resolution has
a "gridline" registration.
"""
data = load_earth_relief(resolution="03s", region=[-10, -9.8, 4.9, 5])
assert data.shape == (121, 241)
assert data.gmt.registration == 0
npt.assert_allclose(data.coords["lat"].data.min(), 4.9)
npt.assert_allclose(data.coords["lat"].data.max(), 5)
npt.assert_allclose(data.coords["lon"].data.min(), -10)
npt.assert_allclose(data.coords["lon"].data.max(), -9.8)
> npt.assert_allclose(data.min(), -2069.996)

../pygmt/tests/test_datasets_earth_relief.py:263:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

args = (.compare at 0x7fb55d6cccc0>, array(-2131.9707, dtype=float32), array(-2069.996))
kwds = {'equal_nan': True, 'err_msg': '', 'header': 'Not equal to tolerance rtol=1e-07, atol=0', 'verbose': True}

@wraps(func)
def inner(*args, **kwds):
with self._recreate_cm():
> return func(*args, **kwds)
E AssertionError:
E Not equal to tolerance rtol=1e-07, atol=0
E
E Mismatched elements: 1 / 1 (100%)
E Max absolute difference: 61.9[747](https://github.com/GenericMappingTools/pygmt/actions/runs/4765800212/jobs/8471996968?pr=2435#step:18:748)0312
E Max relative difference: 0.02993953
E x: array(-2131.9707, dtype=float32)
E y: array(-2069.996)
```