Remove unused Punctuated import

    warning: unused import: `syn::punctuated::Punctuated`
     --> serde_derive/src/internals/receiver.rs:5:5
      |
    5 | use syn::punctuated::Punctuated;
      |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
      |
      = note: `#[warn(unused_imports)]` on by default

Left by the previous commit.

-        let segments = mem::replace(&mut path.segments, Punctuated::new());
+        let segments = mem::take(&mut path.segments);

Author: dtolnay

serde_derive/src/internals/receiver.rs

@@ -2,7 +2,6 @@ use crate::internals::respan::respan;
 use proc_macro2::Span;
 use quote::ToTokens;
 use std::mem;
-use syn::punctuated::Punctuated;
 use syn::{
     parse_quote, Data, DeriveInput, Expr, ExprPath, GenericArgument, GenericParam, Generics, Macro,
     Path, PathArguments, QSelf, ReturnType, Token, Type, TypeParamBound, TypePath, WherePredicate,