Merge rust-bitcoin#5070: Fix clippy lint with no-default-features in primitives and units

0408f3d Fix unused clippy lint (Jamil Lambert, PhD)
67eea0b Fix explicit lifetime clippy lint (Jamil Lambert, PhD)
1363dc6 Fix unused import clippy lint (Jamil Lambert, PhD)

Pull request description:

  There are a few lint errors in `units` and `primitives` with `no-default-features`.
  
  Fix the lint errors in `units` and `primitives` with `no-default-features`.


ACKs for top commit:
  apoelstra:
    ACK 0408f3d; successfully ran local tests
  tcharding:
    ACK 0408f3d


Tree-SHA512: d2b2ae03bcf021dd8f62e88850c61f0e41f09497778278bb8f16c82567aa9f1f3a9df14b4a7157c75eac9b2fb70602f8a1a12dbc9f311029b54bdc8f7c085a30

Author: apoelstra

consensus_encoding/src/encode/encoders.rs

@@ -101,7 +101,7 @@ impl<'e, T: Encodable> SliceEncoder<'e, T> {
     }
 }
 
-impl<'e, T: Encodable> Encoder for SliceEncoder<'e, T> {
+impl<T: Encodable> Encoder for SliceEncoder<'_, T> {
     fn current_chunk(&self) -> Option<&[u8]> {
         if let Some(compact_size) = self.compact_size.as_ref() {
             return Some(compact_size);

primitives/src/lib.rs

@@ -41,6 +41,7 @@ pub mod _export {
 }
 
 mod hash_types;
+#[cfg(feature = "alloc")]
 mod opcodes;
 
 pub mod block;

units/src/amount/tests.rs

@@ -11,7 +11,9 @@ use core::num::{NonZeroI64, NonZeroU64};
 use std::panic;
 
 use super::*;
-use crate::result::{MathOp, NumOpResult};
+use crate::result::NumOpResult;
+#[cfg(feature = "alloc")]
+use crate::result::MathOp;
 #[cfg(feature = "alloc")]
 use crate::{FeeRate, Weight};