[Error] Show warning when serialize=True is set on a struct for (#4844)
[Error] Show warning when serialize=True is set on a struct for (#4844)

* [Error] Show warning when serialize=True is set on a struct for

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <3ea08453efb076ca910552532a53973a6527df40@users.noreply.github.com>
yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi