Add missing atol argument to floating-point test (#10439) (#10440)

The other assertion in this test has the `atol` parameter, but this one
is missing it, which can occasionally lead to off-by-one-bit differences
in the complex multiplication outputs.

(cherry picked from commit fafb750)

Co-authored-by: Jake Lishman <jake.lishman@ibm.com>

test/python/quantum_info/operators/symplectic/test_sparse_pauli_op.py

@@ -601,7 +601,7 @@ def test_mul(self, num_qubits, value, param):
         if value == 0:
             np.testing.assert_array_equal(value_mat, target.astype(complex))
         else:
-            np.testing.assert_allclose(value_mat, target)
+            np.testing.assert_allclose(value_mat, target, atol=1e-8)
         np.testing.assert_array_equal(op.paulis.phase, np.zeros(op.size))
         target = spp_op.to_matrix() * value
         op = spp_op * value