[clang-tools-extra] [clangd] Allow specifying what headers are always included via "" or <> (PR #67749)

[kleines Filmröllchen via cfe-commits]

kleinesfilmroellchen wrote:

I don't have any energy and the massive reachitecting requested would take me tons of time. Please adopt this. Serenity folks are also waiting fwiw

https://github.com/llvm/llvm-project/pull/67749