Remove erroneous test that relied on bitwidth parameter for hash table construction

I've removed the bitwidth parameter for construction and opted for this to be calculated
internally for optimal memory footprint and query cost

Author: fluidnumericsJoe

tests/test_spatialhash.py

@@ -60,20 +60,6 @@ def test_spherical_regional_bounds():
     assert np.all(i == -3)
 
 
-def test_query_honors_reduced_bitwidth():
-    """Queries must be encoded at the same quantization resolution the table was
-    built with; a mismatch makes every Morton key miss and all queries fail.
-    """
-    ds = datasets["2d_left_rotated"]
-    grid = FieldSet.from_sgrid_conventions(ds, mesh="spherical").data_g.grid
-    spatialhash = SpatialHash(grid, bitwidth=64)
-
-    clat, clon, jj, ii = _cell_centers(grid)
-    j, i, _ = spatialhash.query(clat.ravel(), clon.ravel())
-    assert np.array_equal(j, jj.ravel())
-    assert np.array_equal(i, ii.ravel())
-
-
 def test_hash_entry_budget():
     """When the requested bitwidth would blow the hash-entry budget (e.g. tilted
     regional spherical meshes, where face bounding boxes overlap 3-D blocks of