[clang-tools-extra] [clang-tidy] Add modernize-default-arg-braced-init check (PR #203474)

[Zeyi Xu via cfe-commits]

zeyi2 wrote:

We have an AI Policy: https://llvm.org/docs/AIToolPolicy.html

> An important implication of this policy is that it bans agents that take action in our digital spaces without human approval, such as the GitHub [@claude agent](https://github.com/claude/). Similarly, automated review tools that publish comments without human review are not allowed.

Please disable the automatic Github Copilot review, thanks.

https://github.com/llvm/llvm-project/pull/203474