[clang-tools-extra] [clangd] Add tweak to override pure virtuals (PR #139348)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

> If you're looking for a clangd reviewer, perhaps one of our other clangd maintainers, @llvm-beanz or @kadircet, could help with this one.

(I realized you are probably not able to edit the Reviewers field, so I went ahead and added the mentioned folks.)

https://github.com/llvm/llvm-project/pull/139348