[clang] [clang][www] Remove ClangDataFormat.py from docs (PR #117943)

[Maksim Ivanov via cfe-commits]

emaxx-google wrote:

Thanks for the review and for the merge!

> Not sure how well maintained these are either, but since they still exist, LGTM

If you mean the `lldbDataFormatters.py` script, then I don't know either, but at least when I tried it it turned out to be useful.

https://github.com/llvm/llvm-project/pull/117943