Resolve redundant import warning

    warning: the item `Vec` is imported redundantly
       --> src/lib.rs:103:5
        |
    103 | use crate::alloc::vec::Vec;
        |     ^^^^^^^^^^^^^^^^^^^^^^
    ...
    109 | use crate::backport::*;
        |     ------------------ the item `Vec` is already imported here
        |
        = note: `#[warn(unused_imports)]` on by default

src/lib.rs

@@ -100,7 +100,6 @@ mod parse;
 #[cfg(feature = "serde")]
 mod serde;
 
-use crate::alloc::vec::Vec;
 use crate::identifier::Identifier;
 use core::cmp::Ordering;
 use core::str::FromStr;