As discussed in PR#5421, capturing `@error` is inconsistent, requiring
deep nesting (or priority) in order to correctly have red backgrounds to
it.
Some queries has this capture, some don't. For consistency purposes,
removing all of them is more preferable.
For re-enabling error, either add `(ERROR) @error` or `(ERROR _ @error)`
to your custom queries.
After https://github.com/nvim-treesitter/nvim-treesitter/issues/470,
we decided to use `@conditional` for ternary operator instead of
operator despite `@conditional` is documented for keywords only.
A sub-scoping can make it easier for people to highlight this operator
group differently.
Also unify the usage of `@conditional...` across languages.
