fix: allow clippy::redundant_clone and clippy::type_complexity in abigen

[georgewhewell]

Motivation

some files generated by abigen do not lint with clippy- e.g.

warning: redundant clone
   --> src/data_sources/bindings/frax_abi.rs:812:73
    |
812 |             if let Ok(decoded) = WithdrawnLockedFilter::from_token(token.clone()) {
    |                                                                         ^^^^^^^^ help: remove this
    |
note: this value is dropped without further use

warning: very complex type used. Consider factoring parts into `type` definitions
   --> src/data_sources/bindings/frax_abi.rs:174:14
    |
174 |           ) -> ethers::contract::builders::ContractCall<
    |  ______________^
175 | |             M,
176 | |             Vec<(
177 | |                 [u8; 32],
...   |
182 | |             )>,
183 | |         > {
    | |_________^
    |
    = note: `#[warn(clippy::type_complexity)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity

Solution

adds #![allow(clippy::redundant_clone)] and #![allow(clippy::type_complexity)] to abigen

PR Checklist

• Added Tests
• Added Documentation
• Updated the changelog

[gakonst]

LGTM - thank you, @mattsse are there maybe any improvements we can make to the codegen to have less lints skipped?