Refine from pedantic, remove erratic consts

common/db/src/lib.rs

@@ -82,7 +82,6 @@ impl Default for MemDb {
 
 impl MemDb {
   /// Create a new in-memory database.
-  #[must_use]
   pub fn new() -> Self {
     Self::default()
   }

common/std-shims/src/io.rs

@@ -24,17 +24,14 @@ mod shims {
   }
 
   impl Error {
-    #[must_use]
     pub fn new<E: 'static + Send + Sync>(kind: ErrorKind, error: E) -> Self {
       Self { kind, error: Box::new(error) }
     }
 
-    #[must_use]
     pub const fn kind(&self) -> ErrorKind {
       self.kind
     }
 
-    #[must_use]
     pub fn into_inner(self) -> Option<Box<dyn Send + Sync>> {
       Some(self.error)
     }