[bug] quantaichi examples using deprecated Taichi interfaces

[jim19930609]

From forum: https://forum.taichi.graphics/t/quantaichi-main/2803

Some quantaichi examples are broken due to the use of deprecated Taichi interfaces.

Let's fix quantaichi examples then add a simple CI to monitor whether they're in sync with latest Taichi release (make it part of the release test?).

[strongoier]

It seems that my PR last month hasn't been merged yet (https://github.com/taichi-dev/quantaichi/pull/3) :-) cc: @k-ye @yuanming-hu