remove JSON since the hook breaks ipynb files

[njzjz]

Clang-format 19 breaks ipynb files. xref: llvm/llvm-project#110727 I can't find a way to exclude a format in pre-commit-mirror, so I remove the JSON format directly to ensure the hook doesn't break any files with the default configuration.

[asottile]

seems best for now to just override this in your own config (probably with exclude: ?) assuming this will get fixed upstream

[njzjz]

The upstream has closed llvm/llvm-project#110727 without a fix.

[Timple]

llvm/llvm-project#135137 was merged and has landed in version LLVM 21.1.0-rc1