[clang-tools-extra] [clang-doc] Replace HTML-CHECK commands with HTML-CHECK-NEXT commands (PR #181330)

[Paul Kirth via cfe-commits]

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

I think this is fine now. We could probably slice up the checks in lots of different ways, but this seems OK to me. @evelez7 could you take another pass at this and make sure you're OK w/ the convention?

Also, do you have commit access? Or do you need one of us to land this PR for you? 

https://github.com/llvm/llvm-project/pull/181330