[clang] [clang] Enable C++17 relaxed template template argument matching by default (PR #89807)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

@joanahalili This is now merged in main: https://github.com/llvm/llvm-project/pull/92324

You can pass `-Wno-deprecated-no-relaxed-template-template-args` to disable the deprecation warning for `-fno-relaxed-template-template-args` specifically, without affecting other warnings.

https://github.com/llvm/llvm-project/pull/89807