fix(jsx): avoid making type param lists ambiguous when trailingCommas is never

[xandris]

Hello, this is the first Rust I've ever read/written. I'd like to fix #636. The guards against mangling type parameter lists were in place but deactivated by trailingCommas: never. Change it to always check before applying the preferred style.

I noticed it checked for function<T> as well, but in my testing neither function expressions nor declarations are ambiguous:

// These parse correctly even in TSX
function foo<T>() { }
const foo = function<T>() {}
class foo<T>() { }
const foo = class<T>() {}

The presence of the function or class keywords seems to be enough for the TypeScript parser to disambiguate.

Thank you, dprint and its plugins are such a delight.