remove recursion limit (#3348)

According to the
[doc](https://doc.rust-lang.org/reference/attributes/limits.html), the
default is 128, so no point to specify limit with 128

Co-authored-by: Bastian Köcher <git@kchr.de>

substrate/frame/support/procedural/tools/derive/src/lib.rs

@@ -19,8 +19,6 @@
 //! Use to derive parsing for parsing struct.
 // end::description[]
 
-#![recursion_limit = "128"]
-
 use proc_macro::TokenStream;
 use proc_macro2::Span;
 use quote::quote;