Remove the deprecation codes

[omid]

After updating chrono-tz we see some deprecated APIs.
chrono itself is still using the deprecated API, we can also wait till they fix it.

For example, here is one of our deprecated impls:

Now when I go to chrono's Local impl, you see they use a deprecated method also (My IDE didn't mark it as deprecared, but it is the one!)
And the whole trait method is also marked as deprecated.

AFAICS, this impl TimeZone for we have, is kinda combination of its impl for chrono's Local and chorono-tz's Tz, which you can find them here and here.