[Luau] Explicit type parameter instantiation syntax is not supported

It seems that attempting to use [explicit type parameter instantiation syntax](https://rfcs.luau.org/explicit-type-parameter-instantiation.html) (or "turbofish"), which has been implemented for a little while now, causes StyLua to throw an error. Example Luau code: ```luau -- test.luau local function f<T>(x: T) return x end local a = f<<number?>>(nil) ``` Stylua command: ```powershell stylua .\test.luau --syntax Luau ``` Error output: ``` error: could not format file .\test.luau: error parsing: - unexpected token `<` (6:12 to 6:13), expected expression after binary operator - unexpected token `<` (6:13 to 6:14), unexpected token, this needs to be a statement - unexpected token `?` (6:20 to 6:21), unexpected expression when looking for a statement - unexpected token `?` (6:20 to 6:21), unexpected token, this needs to be a statement - unexpected token `` (6:28 to 6:28), unexpected expression when looking for a statement ```