[clang-tools-extra] [clangd] don't lower severity of clang-tidy modernize-* checks to remarks (PR #75706)

[Julian Schmidt via cfe-commits]

5chmidti wrote:

The tag for `modernize-*` checks gets added here:
https://github.com/llvm/llvm-project/blob/f49e2b05bf3ececa2fe20c5d658ab92ab974dc36/clang-tools-extra/clangd/Diagnostics.cpp#L392-L397

https://github.com/llvm/llvm-project/pull/75706