`tanh` returns wrong result for `inf + 2j`

[antonwolfy]

The following example breaks Python array API:

dpctl.__version__
# Out: '0.22.0dev0+114.g0797836be2'

a = dpt.asarray(complex(np.inf, 2))

dpt.tanh(a)
# Out: usm_ndarray(1.-0.j)

but the spec states:

If a is +infinity and b is a positive (i.e., greater than 0) finite number, the result is 1 + 0j.