[clang-tools-extra] [clang-tidy] Remove enforcement of rule C.48 from cppcoreguidelines-p… (PR #80193)

[Piotr Zegar via cfe-commits]

https://github.com/PiotrZSL approved this pull request.

Looks fine.

For me check names are not the best, it's hard to figure out what they does. Maybe they should be named like prefer-using-initialization-list and prefer-using-in-class-initializers.
Simply because now member initializer could be both an in class and on initialization list.

Second thing is that would be nice if changed check name is more early in release notes, like "Changed/Improved cppcoreguidelines-prefer-member-initializer by removing enforcement of rule C.48, , deprecated since :program:clang-tidy 17. This rule is now covered by cppcoreguidelines-use-default-member-init check."

I didn't check too deeply changed, code after all that's mainly code removal, and that's covered by tests.

https://github.com/llvm/llvm-project/pull/80193