[clang-tools-extra] [clang-tidy] Enable `modernize-return-braced-init-list`'s tests in C++11 (PR #158196)

[Baranov Victor via cfe-commits]

vbvictor wrote:

> The change will make it test only in C++17, won't it? Don't we want c++11-or-later instead?

It will be c++11 by default:
https://github.com/llvm/llvm-project/blob/111de45e838a7d33637da8807212284c988f7fae/clang-tools-extra/test/clang-tidy/check_clang_tidy.py#L392-L394

https://github.com/llvm/llvm-project/pull/158196