Bump clippy to Rust 1.81 (#1225)

Also fixes clippy warnings

Author: tony-iqlusion

.github/workflows/workspace.yml

@@ -25,7 +25,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.70.0 # MSRV
+          toolchain: 1.81.0 # pinned to prevent breakages
           components: clippy
           override: true
           profile: minimal

secrecy/src/lib.rs

@@ -88,7 +88,7 @@ impl<S: Zeroize + ?Sized> SecretBox<S> {
     }
 }
 
-impl<S: Zeroize + Default + ?Sized> SecretBox<S> {
+impl<S: Zeroize + Default> SecretBox<S> {
     /// Create a secret value using a function that can initialize the value in-place.
     pub fn init_with_mut(ctr: impl FnOnce(&mut S)) -> Self {
         let mut secret = Self::default();
@@ -97,7 +97,7 @@ impl<S: Zeroize + Default + ?Sized> SecretBox<S> {
     }
 }
 
-impl<S: Zeroize + Clone + ?Sized> SecretBox<S> {
+impl<S: Zeroize + Clone> SecretBox<S> {
     /// Create a secret value using the provided function as a constructor.
     ///
     /// The implementation makes an effort to zeroize the locally constructed value
@@ -130,7 +130,7 @@ impl<S: Zeroize + Clone + ?Sized> SecretBox<S> {
     }
 }
 
-impl<S: Zeroize + ?Sized + Default> Default for SecretBox<S> {
+impl<S: Zeroize + Default> Default for SecretBox<S> {
     fn default() -> Self {
         Self {
             inner_secret: Box::<S>::default(),