[llvm] [lldb] Add lldb team to CODEOWNERS (PR #65454)

[Jonas Devlieghere via llvm-commits]

JDevlieghere wrote:

> The warning isn't shown for [pr-subscribers-x86](https://github.com/orgs/llvm/teams/pr-subscribers-x86) so there's something different about the lldb team.

I can't see any difference between @llvm/pr-subscribers-x86 and @llvm/pr-subscribers-lldb.

@tstellar Could you have a look? You might see more than we can? 

https://github.com/llvm/llvm-project/pull/65454